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    <content type="html"><![CDATA[<p>Welcome to <a href="https://hexo.io/">Hexo</a>! This is your very first post. Check <a href="https://hexo.io/docs/">documentation</a> for more info. If you get any problems when using Hexo, you can find the answer in <a href="https://hexo.io/docs/troubleshooting.html">troubleshooting</a> or you can ask me on <a href="https://github.com/hexojs/hexo/issues">GitHub</a>.</p><h2 id="Quick-Start">Quick Start</h2><h3 id="Create-a-new-post">Create a new post</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo new <span class="string">&quot;My New Post&quot;</span></span><br></pre></td></tr></table></figure><p>More info: <a href="https://hexo.io/docs/writing.html">Writing</a></p><h3 id="Run-server">Run server</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo server</span><br></pre></td></tr></table></figure><p>More info: <a href="https://hexo.io/docs/server.html">Server</a></p><h3 id="Generate-static-files">Generate static files</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo generate</span><br></pre></td></tr></table></figure><p>More info: <a href="https://hexo.io/docs/generating.html">Generating</a></p><h3 id="Deploy-to-remote-sites">Deploy to remote sites</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo deploy</span><br></pre></td></tr></table></figure><p>More info: <a href="https://hexo.io/docs/one-command-deployment.html">Deployment</a></p>]]></content>
    
    
      
      
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    <title>机器视觉</title>
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    <content type="html"><![CDATA[<h1>主观题（AI纯度100%）</h1><p><strong>1. 像素及其特点</strong><br>像素(pixel) 是构成数字图像的基本单元，每个像素都有明确的位置和颜色信息，共同组成了完整的图像。<br>像素特点：每个像素都是不可分的最小单元；具有整数的行和列位置坐标和整数的灰度值。</p><p><strong>2. 数字图像及特点</strong><br>数字图像是由模拟图像数字化得到的、以像素为基本元素的、可用数字计算机或电路存储和处理的图像。数字图像的特点包括：</p><ul><li>离散性：数字图像是连续图像的离散化表示，像素是离散的点，而不是连续的颜色变化。</li><li>量化：数字图像的颜色信息经过量化处理，通常使用有限的颜色值表示。</li><li>可处理性：数字图像可以通过计算机算法进行处理和分析。</li></ul><p><strong>3. 图像的数字化</strong><br>图像的数字化是将连续图像信号转换为离散数字信号的过程，主要包括采样和量化两个步骤。</p><p><strong>4. 数字图像采样</strong><br>数字图像采样是指在图像的空间域内，以一定的间隔对连续图像进行取样，形成离散的像素点。</p><p><strong>5. 图像空间分辨率</strong><br>图像空间分辨率是指图像中所包含的像素数量，通常用每单位面积的像素数来表示，分辨率越高，图像细节越丰富。</p><p><strong>6. 灰度图像</strong><br>灰度图像是指仅包含亮度信息的图像，每个像素用一个灰度值表示，通常范围在0到255之间。</p><p><strong>7. 24位真彩色图像</strong><br>一般的彩色图像是用RGB三基色表示，每个像素包括红绿蓝三种颜色的数据，每个数据用1个字节（8位二进制位）表示，则每个像素的数据为3个字节（即24位二进制位）。</p><p><strong>8. RGB图像</strong><br>RGB图像是指使用红、绿、蓝三种颜色通道来表示颜色信息的图像，每个像素由三个分量值组成。</p><p><strong>9. HSI彩色空间</strong><br>HSI彩色空间是一种基于色调(Hue)、饱和度(Saturation)和亮度(Intensity)的颜色表示方式，常用于图像处理和分析。</p><p><strong>10. 图像压缩编码</strong><br>图像压缩编码是指对图像数据进行编码以减少其存储空间和传输带宽的过程，常用的方法包括无损压缩和有损压缩。</p><p><strong>11. 有损压缩</strong><br>有损压缩是指在压缩过程中丢失部分图像信息的压缩方法，通常能够获得更高的压缩比，但会影响图像质量。</p><p><strong>12. 图像冗余</strong><br>图像冗余是指图像中存在的多余信息，包括空间冗余、时域冗余、频域冗余和信息熵冗余，压缩算法通过去除冗余信息来减小图像文件大小。</p><p><strong>13. 图像平滑滤波</strong><br>图像平滑滤波是指通过一定的滤波器对图像进行处理，以减少图像中的噪声，常用的方法包括邻域平均法、中值滤波和多图像平均法。</p><p><strong>14. 图像均值滤波</strong><br>图像均值滤波是指通过计算图像中每个像素周围邻域的平均值来替代该像素的值，从而达到平滑图像的效果。</p><p><strong>15. 高斯滤波</strong><br>高斯滤波是一种加权平均滤波方法，通过对像素周围的像素值进行高斯加权平均来实现平滑效果，能够有效去除高频噪声。</p><p><strong>16. 中值滤波</strong><br>中值滤波是一种非线性滤波方法，通过取像素邻域内的中值来替代该像素的值，能够有效去除椒盐噪声。</p><p><strong>17. 图像噪声</strong><br>图像噪声是指在图像采集、传输和处理过程中引入的随机干扰信号，常见的噪声类型包括高斯噪声、椒盐噪声和瑞利噪声。</p><p><strong>18. 频域去噪声</strong><br>频域去噪声是指通过频域分析和处理来去除图像中的噪声，常用的方法包括傅里叶变换和小波变换。</p><p><strong>19. 图像低频分量及特点</strong><br>图像低频分量是指图像中变化较缓慢的部分，通常包含图像的整体轮廓和大致形状。</p><p><strong>20. 图像高频分量及特点</strong><br>图像高频分量是指图像中变化较快的部分，通常包含图像的细节和边缘信息。</p><p><strong>21. 频域变化</strong><br>频域变化是图像处理中一种去噪声滤波和提取边缘特征的方法，通过傅里叶变换，将图像的空间像素变换为图像的频域幅度。</p><p><strong>22. 图像增强</strong><br>图像增强是指通过各种技术手段提高图像的视觉效果，使其更适合人眼观察或后续处理。</p><p><strong>23. 图像灰度拉伸变换</strong><br>图像灰度拉伸变换是指通过线性变换调整图像的灰度值范围，以增强图像的对比度。</p><p><strong>24. 负相式灰度变换</strong><br>负相式灰度变换是指将图像的灰度值取反，以实现图像的反转效果。</p><p><strong>25. 灰度直方图的归一化</strong><br>灰度直方图的归一化是指对图像的灰度直方图进行处理，使其符合一定的分布规律，常用于图像增强。</p><p><strong>26. 灰度阈值分割</strong><br>灰度阈值分割是指通过设定灰度阈值，将图像分割为前景和背景，常用于目标检测和分割。</p><p><strong>27. 二值图像</strong><br>二值图像是指仅包含黑白两种颜色的图像，每个像素只有0和1两个取值，常用于图像分割和特征提取。</p><p><strong>28. 区域分割</strong><br>区域分割是利用图像的空间性质，认为分割出来的属于同一区域的像素应具有相似的性质。传统的区域分割法有区域生长法和分裂合并法。</p><p><strong>29. 区域生长</strong><br>区域生长是一种基于种子点的区域分割方法，通过逐步将相似的邻域像素合并到区域中。</p><p><strong>30. 四叉树分裂合并</strong><br>四叉树分裂合并是一种基于四叉树结构的图像分割方法，通过对图像进行分裂和合并操作来实现分割。</p><p><strong>31. 图像分割与描述</strong><br>图像分割与描述是指对图像进行分割后，对各个分割区域进行特征提取和描述。</p><p><strong>32. 图像边缘检测</strong><br>图像边缘检测是指通过算法检测图像中亮度变化较大的区域，以提取出物体的边缘信息。</p><p><strong>33. 图像区域的矩形度</strong><br>图像区域的矩形度是指区域的外接矩形与区域本身的面积之比，用于衡量区域的形状特征。</p><p><strong>34. 图像区域的圆度</strong><br>图像区域的圆度是指区域的面积与外接圆的面积之比，用于衡量区域的圆形程度。</p><p><strong>35. 欧式距离和城市距离</strong><br>欧式距离是指两点之间的直线距离，城市距离是指在网格状路径上行走的距离，通常用于度量图像中像素之间的相似性。</p><p><strong>36. 边界链码描述</strong><br>边界链码描述是一种用于表示图像中物体边界的方式，通过链码可以有效地描述边界的形状特征。</p><p><strong>37. 纹理描述</strong><br>图像中，对局部不规则而宏观有规律的灰度变化的描述，叫做纹理描述，大致分为统计分析和结构分析两大类。</p><h1>简答题</h1><p><strong>1. 举例说明图像加法运算与应用。</strong><br>加法运算，将两幅原始图像对应位置处，两个像素的灰度值相加得到一个新的灰度值，作为结果图像对应位置处像素的灰度值。<br>应用：</p><ul><li>提高图像的整体亮度，或者降低图像整体亮度</li><li>将两幅图像进行融合。</li><li>将多幅带有噪声干扰的图像进行叠加平均，可以降低图像的噪声干扰。</li></ul><p><strong>2. 数字图像类型及其特点(真彩色、索引、灰度、二值)。</strong></p><ul><li>真彩色图像：每个像素用24位二进制数表示颜色信息，通常分为8位红色、8位绿色和8位蓝色通道。</li><li>索引图像：每个像素用一个索引值表示颜色，这些索引值指向一个颜色表，颜色表中存储了实际的颜色值，常用于减少存储空间。</li><li>灰度图像：仅包含亮度信息，每个像素用一个灰度值表示，通常范围在0到255之间。</li><li>二值图像：仅包含黑白两种颜色的图像，每个像素只有0和1两个取值，常用于图像分割和特征提取。</li></ul><p><strong>3. 画图说明RGB彩色空间。</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/6af36306801fd51aef2767cbda270eda.png" alt=""></p><p><strong>4. 画图说明HSI彩色空间。</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/7df46229ba108602eafd27ed4ce753b4.png" alt=""></p><p><strong>5. 举例说明伪彩色图像增强处理的应用。</strong><br>伪彩色图像增强处理是将灰度图像转换为彩色图像，以增强图像的可视化效果。常见应用包括：</p><ul><li>医学图像处理：将灰度医学图像转换为彩色图像，以突出病变区域。</li><li>遥感图像处理：将灰度遥感图像转换为彩色图像，以便更好地识别地物特征。</li><li>工业检测：将灰度工业检测图像转换为彩色图像，以便更好地识别缺陷或异常。</li></ul><p><strong>6. 数字图像处理的发展趋势。</strong></p><ul><li>从低分辨率向高分辨率发展</li><li>从二维（2D）向三维（3D）发展</li><li>从静止图像向动态图像发展</li><li>从单态图像向多态图像发展</li><li>从图像处理向图像理解发展</li></ul><p><strong>7. 画图说明水平、垂直、对角方向的边缘检测算子模板。</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/54fc7d84b73d8f20fd07d5b0920690f5.png" alt=""><br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/620b9674a5673cd2b092a202c164b329.png" alt=""><br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/07/974c144bfe8f10813cbf1ada66b7c947.png" alt=""></p><p><strong>8. 画图说明低通滤波过程。</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/12277fc235ca002140acff52b08a3c14.png" alt=""></p><p><strong>9. 画图说明图像处理、分析和理解之间关系。</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/3d31eeb0d1b3ab47dbd1f5d34513a1fe.png" alt=""></p><p><strong>10. 举例说明图像乘法运算与应用</strong><br>图像乘法运算是将两幅原始图像对应位置处，两个像素的灰度值相乘得到一个新的灰度值，作为结果图像对应位置处像素的灰度值。<br>应用：</p><ul><li>掩膜效果。</li></ul><p><strong>11. 画图简述Susan算子检测角点原理。(答案)</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/7f441653330d5cd5f673d917d10c429e.png" alt=""></p><p><strong>12. 说明题图中T点具有的特性。</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/0751779485fb6b27458b387e34faa37c.png" alt=""></p><p><strong>14. 画图说明带通滤波过程。</strong></p><p><strong>15. 简述图像纹理分析的作用。</strong></p><ul><li>目标识别与分类</li><li>图像分割</li><li>缺陷检测</li><li>医学图像分析</li><li>视觉内容理解</li></ul><p><strong>16. 画图说明机器视觉成像系统组成。（答案）</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/0834d32d57e1fa2d748e6e7e4ffb74b5.png" alt=""></p><p><strong>17. 举例说明图像逻辑运算的应用。</strong></p><ul><li>图像掩膜（Masking）与区域提取</li><li>图像融合与前景合成</li><li>图像反转（负片处理）</li><li>运动检测或目标变化检测</li></ul><p><strong>18. 画图说明图像数字化过程。</strong></p><p><strong>19. 画图说明BP神经网络的结构。</strong></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/07/51a5c9e3ceba9417a648e3d7cf5845eb.png" alt=""></p><p><strong>20. 举例说明灰度窗口变换的应用。</strong></p><ul><li>图像与背景分割</li></ul><p><strong>21. 举例说明监督学习和无监督学习的区别</strong></p><ul><li>监督学习：使用带标签的训练数据进行学习，目标是学习一个映射函数，以便对新数据进行预测。</li><li>无监督学习：使用无标签的训练数据进行学习，目标是发现数据中的潜在结构或模式。</li></ul><p><strong>22. 举例说明图像减法运算与应用。</strong><br>图像减法运算是将两幅原始图像对应位置处，两个像素的灰度值相减得到一个新的灰度值，作为结果图像对应位置处像素的灰度值。<br>应用：</p><ul><li>背景建模与去除</li><li>运动检测</li><li>变化检测</li></ul><h1>综合题</h1><ol><li>综合利用图像处理和分析方法，说明身份证号码字符识别过程，可能遇到的问题和解决方法。</li></ol><p>识别过程主要包括身份证图像采集、图像预处理、字符分割、字符特征提取与识别。</p><p>（1）身份证图像采集时，需选择合适的相机分辨率、光源类型和照明角度，确保图像清晰、无反光和阴影。</p><p>（2）图像预处理，包括图像灰度化、二值化、去噪、对比度增强等操作，以突出身份证号码区域，抑制背景干扰。</p><p>（3）字符分割，通过投影法、连通域分析等方法，将号码区域中的每个字符单独分割出来。</p><p>（4）字符特征提取与识别，采用模板匹配、支持向量机（SVM）、卷积神经网络（CNN）等方法对分割后的字符进行特征提取和分类识别。</p><p>可能遇到的问题及解决方法：</p><ul><li>字符粘连或断裂：可采用形态学处理（如腐蚀、膨胀）或改进分割算法进行优化。</li><li>光照不均、反光、阴影：通过自适应阈值、图像增强等方法改善图像质量。</li><li>字符旋转、倾斜：可利用霍夫变换或仿射变换进行校正。</li><li>字体多样、模糊：采用深度学习方法提升鲁棒性，或采集多样化样本进行训练。</li><li>背景干扰：通过定位号码区域、掩膜处理等方式去除无关信息。</li></ul><ol start="2"><li><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/07/004dab60c43bff72222e0783c00333a4.png" alt=""><br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/07/7dd438e335bbf2a83977f0a10db861db.png" alt=""></p></li><li><p>综合利用图像处理和分析方法，说明车牌字符识别过程，可能遇到的问题和解决方法。</p></li></ol><p>识别过程主要包括车牌图像采集、图像预处理、车牌定位、字符分割、字符特征提取与识别。</p><p>（1）车牌图像采集时，需选择合适的相机分辨率、快门速度和光源，确保车牌区域清晰、无反光和阴影。</p><p>（2）图像预处理，包括灰度化、去噪、对比度增强等操作，以突出车牌区域，抑制背景干扰。</p><p>（3）车牌定位，采用颜色特征、边缘检测、形态学处理等方法，准确定位车牌区域。</p><p>（4）字符分割，通过投影法、连通域分析等方法，将车牌中的每个字符单独分割出来。</p><p>（5）字符特征提取与识别，利用模板匹配、支持向量机（SVM）、卷积神经网络（CNN）等方法对字符进行特征提取和分类识别。</p><p>可能遇到的问题及解决方法：</p><ul><li>车牌污损、模糊：采用图像增强、超分辨率重建等方法提升图像质量。</li><li>光照不均、反光、阴影：通过自适应阈值、图像增强等方法改善图像效果。</li><li>字符粘连或断裂：利用形态学处理或优化分割算法进行修正。</li><li>车牌倾斜、旋转：采用霍夫变换或仿射变换进行校正。</li><li>字体多样、背景复杂：采用深度学习方法提升鲁棒性，或采集多样化样本进行训练。</li></ul><ol start="4"><li>综合利用图像处理和分析方法，说明实现不同等级苹果分类的过程。</li></ol><p>答案：苹果分级主要包括苹果图像采集、图像预处理、特征提取、苹果分级判别等步骤。</p><p>（1）苹果图像采集时，选择合适的相机分辨率、光源类型和照明方式，确保苹果表面特征清晰可见，避免阴影和反光。</p><p>（2）图像预处理，包括图像掩膜处理，去除背景干扰，定位苹果区域；对苹果区域进行灰度化、二值化、滤波降噪、对比度增强等操作。</p><p>（3）特征提取，根据分级标准，提取苹果的颜色、大小、形状、表面缺陷等特征。常用方法有颜色直方图分析、边缘检测、轮廓提取、纹理分析等。</p><p>（4）苹果分级判别，根据提取的特征，采用阈值法、支持向量机（SVM）、决策树、卷积神经网络（CNN）等方法对苹果进行等级分类。</p><p>可能遇到的问题及解决方法：</p><ul><li>光照不均、反光、阴影：通过自适应阈值、图像增强等方法改善图像质量。</li><li>苹果表面有污渍或损伤：采用多特征融合和深度学习方法提升分级准确率。</li><li>苹果重叠或遮挡：优化传送带设计，采用多视角成像或三维重建技术。</li><li>不同品种、颜色差异大：采集多样化样本，优化特征提取和分类算法。</li><li>背景复杂：采用掩膜分割和背景抑制方法，确保苹果区域准确分割。</li></ul><ol start="5"><li>综合利用图像处理和分析方法，说明生产线上药片包装漏放的识别过程。</li></ol><p>答案：识别过程主要包括药片包装图像采集、图像预处理、药片区域定位、药片缺失检测等步骤。</p><p>（1）药片包装图像采集时，选择合适的相机分辨率、光源类型和照明方式，确保药片和包装区域清晰可见，避免反光和阴影。</p><p>（2）图像预处理，包括掩膜处理去除背景干扰，定位药片包装区域，对区域进行灰度化、二值化、滤波降噪、对比度增强等操作。</p><p>（3）药片区域定位，利用模板匹配、边缘检测或形态学方法，准确分割出每个药片所在的标准位置。</p><p>（4）药片缺失检测，对每个标准位置进行像素统计或特征分析，判断是否存在药片。可采用面积、形状、灰度等特征进行判别。</p><p>可能遇到的问题及解决方法：</p><ul><li>光照不均、反光、阴影：通过自适应阈值、图像增强等方法改善图像质量。</li><li>药片颜色或形状多样：采集多样化样本，优化特征提取和分类算法。</li><li>包装位置偏移或变形：采用模板匹配和形态学方法提升定位鲁棒性。</li><li>背景复杂或有杂质：利用掩膜分割和背景抑制方法去除干扰。</li><li>药片破损或碎片：结合面积和形状特征，区分完整药片与异常情况。</li></ul><ol start="6"><li>综合利用图像处理和分析方法，说明生产线上瓶装水液位是否合格的检测过程，可能遇到的问题和解决方法。</li></ol><p>识别过程主要包括瓶装水图像采集、瓶装水液面图像预处理、瓶装水特征提取、瓶装水液面检测。<br>（1）瓶装水图像采集时，计算图像视野、相机像素分辨率、快门时间、镜头焦距等参数，进行相机、镜头的型号选择。</p><p>（2）瓶装水液面图像预处理，对图像进行图像掩膜处理，定位出瓶装水液面位置；然后再进行灰度化、二值化、滤波降噪、对比度提高等处理。</p><p>（3）瓶装水液面特征提取，利用微分算子或者各种边缘检测算子，对液面的边缘进行检测；然后利用Hough方法检测，检测出液面直线。</p><p>（4）根据液面直线的位置，判断瓶装水液面高度是否满足要求。</p><ol start="7"><li><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/07/08ca20d51a4e5a0470b909a2a3052b7d.png" alt=""></p></li><li><p>一幅总像素为n=64×64的8bit数字图像（即灰度级数为8），各灰度级出现的频率列于表中。将此幅图像进行直方图均衡化变换；并画出变换前后的直方图。<br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/07/1f53a83e573e8accb2faa9f00a5c1205.png" alt=""></p></li><li><p>简要说明图像压缩编码的目的；已知符号A、B、C出现的概率分别是0.4, 0.2, 0.4，对符号BACCA进行算术编码，写出编码过程，并进行解码。</p></li><li><p>一幅总像素为n=64×64的8bit数字图像（即灰度级数为8），各灰度级（出现的频率）分布列于表中。要求将此幅图像进行均衡化修正（变换），并画出修正（变换）前后的直方图。<br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/07/e86a94fa774332b1a1c369c177db8ed6.png" alt=""></p></li><li><p>画出用结构元素对图像进行闭运算的结果（先膨胀再腐蚀），边缘保持不变；对闭运算结果，按顺时针，进行8链码边界编码；起始编码点，为闭运算结果的最小行和最小列。</p></li></ol><p>形态学结构元素<br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/07/c339fda09ac7d53a44ceb2a9bb382229.png" alt=""></p><ol start="12"><li>综合利用图像处理和分析方法，说明包装线上不同形状和尺寸的食品识别分拣过程，可能遇到的问题和解决方法。</li></ol><p>答案：识别分拣过程主要包括食品图像采集、图像预处理、食品区域定位、特征提取、分类与分拣等步骤。</p><p>（1）食品图像采集时，选择合适的相机分辨率、光源类型和照明方式，确保不同形状和尺寸的食品在图像中清晰可见，避免阴影和反光。</p><p>（2）图像预处理，包括掩膜处理去除背景干扰，定位食品区域，对区域进行灰度化、二值化、滤波降噪、对比度增强等操作。</p><p>（3）食品区域定位，利用边缘检测、形态学处理或分割算法，准确分割出每个食品的独立区域。</p><p>（4）特征提取，根据分拣需求，提取食品的形状（如圆度、矩形度、长宽比）、尺寸（面积、周长）、颜色、纹理等特征。</p><p>（5）分类与分拣，根据提取的特征，采用阈值法、支持向量机（SVM）、决策树、卷积神经网络（CNN）等方法对食品进行分类，并通过机械臂或分拣装置完成分拣。</p><ol start="13"><li>综合利用图像处理和分析方法，说明包装箱里水瓶的计数统计过程。</li></ol><p>答案：计数统计过程主要包括水瓶图像采集、图像预处理、水瓶区域定位与分割、水瓶计数等步骤。</p><p>（1）水瓶图像采集时，选择合适的相机分辨率、光源类型和照明方式，确保包装箱内水瓶图像清晰、无反光和阴影。</p><p>（2）图像预处理，包括掩膜处理去除背景干扰，定位包装箱区域，对区域进行灰度化、二值化、滤波降噪、对比度增强等操作。</p><p>（3）水瓶区域定位与分割，利用边缘检测、形态学处理或分割算法，准确分割出每个水瓶的独立区域。可采用连通域分析、轮廓提取等方法。</p><p>（4）水瓶计数，对分割出的每个独立水瓶区域进行计数，统计包装箱内水瓶的总数。</p><p>可能遇到的问题及解决方法：</p><ul><li>水瓶重叠或遮挡：采用多视角成像、三维重建或优化分割算法提升分割准确率。</li><li>光照不均、反光、阴影：通过自适应阈值、图像增强等方法改善图像质量。</li><li>包装箱内杂物或背景干扰：利用掩膜分割和背景抑制方法去除无关信息。</li><li>水瓶形状、颜色多样：采集多样化样本，优化特征提取和分割算法。</li><li>水瓶倾斜、旋转：采用形态学处理和轮廓分析提升鲁棒性。</li></ul><ol start="14"><li>综合利用图像处理和分析方法，说明生产线上不同尺寸大小螺丝零件的识别分拣过程，可能遇到的问题和解决方法。</li></ol><p>答案：识别分拣过程主要包括螺丝图像采集、图像预处理、螺丝区域定位、特征提取、分类与分拣等步骤。</p><p>（1）螺丝图像采集时，选择合适的相机分辨率、光源类型和照明方式，确保不同尺寸螺丝在图像中清晰可见，避免阴影和反光。</p><p>（2）图像预处理，包括掩膜处理去除背景干扰，定位螺丝区域，对区域进行灰度化、二值化、滤波降噪、对比度增强等操作。</p><p>（3）螺丝区域定位，利用边缘检测、形态学处理或分割算法，准确分割出每个螺丝的独立区域。</p><p>（4）特征提取，根据分拣需求，提取螺丝的长度、直径、头部形状、螺纹特征等尺寸和形状特征。常用方法有轮廓分析、最小外接矩形、主轴方向等。</p><p>（5）分类与分拣，根据提取的特征，采用阈值法、支持向量机（SVM）、决策树、卷积神经网络（CNN）等方法对螺丝进行尺寸和类型分类，并通过机械臂或分拣装置完成分拣。</p><p>可能遇到的问题及解决方法：</p><ul><li>螺丝重叠或遮挡：采用多视角成像、三维重建或优化分割算法提升分割准确率。</li><li>光照不均、反光、阴影：通过自适应阈值、图像增强等方法改善图像质量。</li><li>背景复杂或有杂物：利用掩膜分割和背景抑制方法去除无关信息。</li><li>螺丝尺寸差异小、形状相似：采用高精度特征提取和深度学习方法提升分类准确率。</li><li>螺丝倾斜、旋转：利用形态学处理和轮廓分析提升鲁棒性。</li></ul><ol start="15"><li>已知符号a1、a2、a3、a4出现的概率分别是0.2, 0.2,0.4, 0.2，对符号a1a2a3a3a4</li></ol><p>进行算术编码，写出编码过程，并进行解码。</p><ol start="16"><li><p>简要说明直方图均衡化的作用；设一幅图像有如图所示直方图，对该图像进行直方图均衡化，写出均衡化过程。</p><p>增强图像的对比度，尤其是在图像的原始直方图分布不均匀，灰度范围较窄的情况下。通过重新分配图像像素的灰度值，使得直方图近似均匀分布，从而提升图像的整体视觉效果和细节表现。</p></li></ol>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;主观题（AI纯度100%）&lt;/h1&gt;
&lt;p&gt;&lt;strong&gt;1. 像素及其特点&lt;/strong&gt;&lt;br&gt;
像素(pixel) 是构成数字图像的基本单元，每个像素都有明确的位置和颜色信息，共同组成了完整的图像。&lt;br&gt;
像素特点：每个像素都是不可分的最小单元；具有整数的行和</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>ros大作业</title>
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    <published>2025-06-07T03:09:52.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>项目概述</h1><p>本大作业利用 ROS  和 Gazebo 仿真环境，实现了一个自主导航建图系统。项目包含以下核心功能：</p><ul><li>在 Gazebo 中创建自定义仿真环境</li><li>搭建移动机器人模型并配置传感器</li><li>使用 gmapping SLAM 算法构建环境地图</li><li>实现自主导航建图功能</li></ul><h1>环境准备</h1><ul><li>Ubuntu16.04</li><li>ROS kinetic版本</li></ul><h1>项目实现</h1><h2 id="1-创建ros工作空间">1. 创建ros工作空间</h2><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">mkdir</span> -p ~/catkin_ws/src</span><br><span class="line"><span class="built_in">cd</span> ~/catkin_ws/src</span><br><span class="line">catkin_init_workspace</span><br><span class="line"><span class="built_in">cd</span> ..</span><br><span class="line">catkin_make</span><br><span class="line"><span class="built_in">source</span> devel/setup.bash</span><br></pre></td></tr></table></figure><p>在 <code>~/catkin_ws/src</code> 目录下引用以下ROS功能包：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">mbot_description</span><br><span class="line">mbot_gazebo</span><br><span class="line">mbot_navigation</span><br></pre></td></tr></table></figure><h2 id="2-创建自定义Gazebo仿真环境">2. 创建自定义Gazebo仿真环境</h2><p>在 <code>~/catkin_ws/src/mbot_gazebo/worlds</code> 下创建一个新的 Gazebo 世界文件 <code>myworld.world</code>，内容如下：</p><figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br><span class="line">83</span><br><span class="line">84</span><br><span class="line">85</span><br><span class="line">86</span><br><span class="line">87</span><br><span class="line">88</span><br><span class="line">89</span><br><span class="line">90</span><br><span class="line">91</span><br><span class="line">92</span><br><span class="line">93</span><br><span class="line">94</span><br><span class="line">95</span><br><span class="line">96</span><br><span class="line">97</span><br><span class="line">98</span><br><span class="line">99</span><br><span class="line">100</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">&lt;?xml version=<span class="string">&quot;1.0&quot;</span>?&gt;</span></span><br><span class="line"><span class="tag">&lt;<span class="name">sdf</span> <span class="attr">version</span>=<span class="string">&quot;1.6&quot;</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">world</span> <span class="attr">name</span>=<span class="string">&quot;default&quot;</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">include</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">uri</span>&gt;</span>model://sun<span class="tag">&lt;/<span class="name">uri</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">include</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">include</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">uri</span>&gt;</span>model://ground_plane<span class="tag">&lt;/<span class="name">uri</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">include</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">model</span> <span class="attr">name</span>=<span class="string">&#x27;ground_plane&#x27;</span>&gt;</span></span><br><span class="line">      <span class="tag">&lt;<span class="name">static</span>&gt;</span>1<span class="tag">&lt;/<span class="name">static</span>&gt;</span></span><br><span class="line">      <span class="tag">&lt;<span class="name">link</span> <span class="attr">name</span>=<span class="string">&#x27;link&#x27;</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">collision</span> <span class="attr">name</span>=<span class="string">&#x27;collision&#x27;</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;<span class="name">geometry</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">plane</span>&gt;</span></span><br><span class="line">              <span class="tag">&lt;<span class="name">normal</span>&gt;</span>0 0 1<span class="tag">&lt;/<span class="name">normal</span>&gt;</span></span><br><span class="line">              <span class="tag">&lt;<span class="name">size</span>&gt;</span>100 100<span class="tag">&lt;/<span class="name">size</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;/<span class="name">plane</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;/<span class="name">geometry</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;<span class="name">surface</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">friction</span>&gt;</span></span><br><span class="line">              <span class="tag">&lt;<span class="name">ode</span>&gt;</span></span><br><span class="line">                <span class="tag">&lt;<span class="name">mu</span>&gt;</span>100<span class="tag">&lt;/<span class="name">mu</span>&gt;</span></span><br><span class="line">                <span class="tag">&lt;<span class="name">mu2</span>&gt;</span>50<span class="tag">&lt;/<span class="name">mu2</span>&gt;</span></span><br><span class="line">              <span class="tag">&lt;/<span class="name">ode</span>&gt;</span></span><br><span class="line">              <span class="tag">&lt;<span class="name">torsional</span>&gt;</span></span><br><span class="line">                <span class="tag">&lt;<span class="name">ode</span>/&gt;</span></span><br><span class="line">              <span class="tag">&lt;/<span class="name">torsional</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;/<span class="name">friction</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">bounce</span>/&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">contact</span>&gt;</span></span><br><span class="line">              <span class="tag">&lt;<span class="name">ode</span>/&gt;</span></span><br><span class="line">            <span class="tag">&lt;/<span class="name">contact</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;/<span class="name">surface</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;<span class="name">max_contacts</span>&gt;</span>10<span class="tag">&lt;/<span class="name">max_contacts</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">collision</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">visual</span> <span class="attr">name</span>=<span class="string">&#x27;visual&#x27;</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;<span class="name">cast_shadows</span>&gt;</span>0<span class="tag">&lt;/<span class="name">cast_shadows</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;<span class="name">geometry</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">plane</span>&gt;</span></span><br><span class="line">              <span class="tag">&lt;<span class="name">normal</span>&gt;</span>0 0 1<span class="tag">&lt;/<span class="name">normal</span>&gt;</span></span><br><span class="line">              <span class="tag">&lt;<span class="name">size</span>&gt;</span>100 100<span class="tag">&lt;/<span class="name">size</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;/<span class="name">plane</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;/<span class="name">geometry</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;<span class="name">material</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">script</span>&gt;</span><span class="language-handlebars"><span class="language-xml"></span></span></span><br><span class="line"><span class="language-xml"><span class="language-handlebars">              <span class="tag">&lt;<span class="name">uri</span>&gt;</span>file://media/materials/scripts/gazebo.material<span class="tag">&lt;/<span class="name">uri</span>&gt;</span></span></span></span><br><span class="line"><span class="language-xml"><span class="language-handlebars">              <span class="tag">&lt;<span class="name">name</span>&gt;</span>Gazebo/Grey<span class="tag">&lt;/<span class="name">name</span>&gt;</span></span></span></span><br><span class="line"><span class="language-xml"><span class="language-handlebars">            </span></span><span class="tag">&lt;/<span class="name">script</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;/<span class="name">material</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">visual</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">velocity_decay</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;<span class="name">linear</span>&gt;</span>0<span class="tag">&lt;/<span class="name">linear</span>&gt;</span></span><br><span class="line">          <span class="tag">&lt;<span class="name">angular</span>&gt;</span>0<span class="tag">&lt;/<span class="name">angular</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">velocity_decay</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">self_collide</span>&gt;</span>0<span class="tag">&lt;/<span class="name">self_collide</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">kinematic</span>&gt;</span>0<span class="tag">&lt;/<span class="name">kinematic</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">gravity</span>&gt;</span>1<span class="tag">&lt;/<span class="name">gravity</span>&gt;</span></span><br><span class="line">      <span class="tag">&lt;/<span class="name">link</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;/<span class="name">model</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">model</span> <span class="attr">name</span>=<span class="string">&quot;cube_red&quot;</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">pose</span>&gt;</span>-10 -3 0 0 0 0<span class="tag">&lt;/<span class="name">pose</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">static</span>&gt;</span>true<span class="tag">&lt;/<span class="name">static</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">link</span> <span class="attr">name</span>=<span class="string">&quot;basic&quot;</span>&gt;</span></span><br><span class="line">                <span class="tag">&lt;<span class="name">collision</span> <span class="attr">name</span>=<span class="string">&quot;collision&quot;</span>&gt;</span></span><br><span class="line">                    <span class="tag">&lt;<span class="name">geometry</span>&gt;</span></span><br><span class="line">                        <span class="tag">&lt;<span class="name">mesh</span>&gt;</span></span><br><span class="line">                            <span class="tag">&lt;<span class="name">uri</span>&gt;</span>/home/jojo/catkin_ws/src/mbot_gazebo/worlds/3.dae<span class="tag">&lt;/<span class="name">uri</span>&gt;</span></span><br><span class="line">                            <span class="tag">&lt;<span class="name">scale</span>&gt;</span>1 1 1<span class="tag">&lt;/<span class="name">scale</span>&gt;</span></span><br><span class="line">                        <span class="tag">&lt;/<span class="name">mesh</span>&gt;</span></span><br><span class="line">                    <span class="tag">&lt;/<span class="name">geometry</span>&gt;</span></span><br><span class="line">                    <span class="tag">&lt;<span class="name">surface</span>&gt;</span></span><br><span class="line">                        <span class="tag">&lt;<span class="name">bounce</span>/&gt;</span></span><br><span class="line">                        <span class="tag">&lt;<span class="name">friction</span>&gt;</span></span><br><span class="line">                            <span class="tag">&lt;<span class="name">ode</span>&gt;</span></span><br><span class="line">                                <span class="tag">&lt;<span class="name">mu</span>&gt;</span>0.8<span class="tag">&lt;/<span class="name">mu</span>&gt;</span></span><br><span class="line">                                <span class="tag">&lt;<span class="name">mu2</span>&gt;</span>0.8<span class="tag">&lt;/<span class="name">mu2</span>&gt;</span></span><br><span class="line">                            <span class="tag">&lt;/<span class="name">ode</span>&gt;</span></span><br><span class="line">                        <span class="tag">&lt;/<span class="name">friction</span>&gt;</span></span><br><span class="line">                    <span class="tag">&lt;/<span class="name">surface</span>&gt;</span></span><br><span class="line">                <span class="tag">&lt;/<span class="name">collision</span>&gt;</span></span><br><span class="line">                <span class="tag">&lt;<span class="name">visual</span> <span class="attr">name</span>=<span class="string">&quot;visual&quot;</span>&gt;</span></span><br><span class="line">                    <span class="tag">&lt;<span class="name">geometry</span>&gt;</span></span><br><span class="line">                        <span class="tag">&lt;<span class="name">mesh</span>&gt;</span></span><br><span class="line">                            <span class="tag">&lt;<span class="name">uri</span>&gt;</span>/home/jojo/catkin_ws/src/mbot_gazebo/worlds/3.dae<span class="tag">&lt;/<span class="name">uri</span>&gt;</span></span><br><span class="line">                            <span class="tag">&lt;<span class="name">scale</span>&gt;</span>1 1 1<span class="tag">&lt;/<span class="name">scale</span>&gt;</span></span><br><span class="line">                        <span class="tag">&lt;/<span class="name">mesh</span>&gt;</span></span><br><span class="line">                    <span class="tag">&lt;/<span class="name">geometry</span>&gt;</span></span><br><span class="line">                    <span class="tag">&lt;<span class="name">material</span>&gt;</span></span><br><span class="line">                      <span class="tag">&lt;<span class="name">script</span>&gt;</span><span class="language-handlebars"><span class="language-xml"></span></span></span><br><span class="line"><span class="language-xml"><span class="language-handlebars">                        <span class="tag">&lt;<span class="name">uri</span>&gt;</span>file://media/materials/scripts/gazebo.material<span class="tag">&lt;/<span class="name">uri</span>&gt;</span></span></span></span><br><span class="line"><span class="language-xml"><span class="language-handlebars">                        <span class="tag">&lt;<span class="name">name</span>&gt;</span>Gazebo/CeilingTiled<span class="tag">&lt;/<span class="name">name</span>&gt;</span></span></span></span><br><span class="line"><span class="language-xml"><span class="language-handlebars">                      </span></span><span class="tag">&lt;/<span class="name">script</span>&gt;</span></span><br><span class="line">                      <span class="tag">&lt;<span class="name">ambient</span>&gt;</span>1 1 1 1<span class="tag">&lt;/<span class="name">ambient</span>&gt;</span></span><br><span class="line">                    <span class="tag">&lt;/<span class="name">material</span>&gt;</span></span><br><span class="line">                <span class="tag">&lt;/<span class="name">visual</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;/<span class="name">link</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">model</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;/<span class="name">world</span>&gt;</span></span><br><span class="line"><span class="tag">&lt;/<span class="name">sdf</span>&gt;</span></span><br></pre></td></tr></table></figure><p>在 <code>~/catkin_ws/src/mbot_gazebo/launch</code> 目录下添加launch文件 <code>mygazebo.launch</code>，内容如下：</p><figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br></pre></td><td class="code"><pre><span class="line"><span class="tag">&lt;<span class="name">launch</span>&gt;</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">&lt;!-- 设置launch文件的参数 --&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;world_name&quot;</span> <span class="attr">value</span>=<span class="string">&quot;$(find mbot_gazebo)/worlds/myworld.world&quot;</span>/&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;paused&quot;</span> <span class="attr">default</span>=<span class="string">&quot;false&quot;</span>/&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;use_sim_time&quot;</span> <span class="attr">default</span>=<span class="string">&quot;true&quot;</span>/&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;gui&quot;</span> <span class="attr">default</span>=<span class="string">&quot;true&quot;</span>/&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;headless&quot;</span> <span class="attr">default</span>=<span class="string">&quot;false&quot;</span>/&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;debug&quot;</span> <span class="attr">default</span>=<span class="string">&quot;false&quot;</span>/&gt;</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">&lt;!-- 运行gazebo仿真环境 --&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">include</span> <span class="attr">file</span>=<span class="string">&quot;$(find gazebo_ros)/launch/empty_world.launch&quot;</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;world_name&quot;</span> <span class="attr">value</span>=<span class="string">&quot;$(arg world_name)&quot;</span> /&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;debug&quot;</span> <span class="attr">value</span>=<span class="string">&quot;$(arg debug)&quot;</span> /&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;gui&quot;</span> <span class="attr">value</span>=<span class="string">&quot;$(arg gui)&quot;</span> /&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;paused&quot;</span> <span class="attr">value</span>=<span class="string">&quot;$(arg paused)&quot;</span>/&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;use_sim_time&quot;</span> <span class="attr">value</span>=<span class="string">&quot;$(arg use_sim_time)&quot;</span>/&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">arg</span> <span class="attr">name</span>=<span class="string">&quot;headless&quot;</span> <span class="attr">value</span>=<span class="string">&quot;$(arg headless)&quot;</span>/&gt;</span></span><br><span class="line">    <span class="tag">&lt;/<span class="name">include</span>&gt;</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">&lt;!-- 加载机器人模型描述参数 --&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">param</span> <span class="attr">name</span>=<span class="string">&quot;robot_description&quot;</span> <span class="attr">command</span>=<span class="string">&quot;$(find xacro)/xacro --inorder &#x27;$(find mbot_description)/urdf/xacro/gazebo/mbot_with_laser_gazebo.xacro&#x27;&quot;</span> /&gt;</span> </span><br><span class="line"></span><br><span class="line">    <span class="comment">&lt;!-- 运行joint_state_publisher节点，发布机器人的关节状态  --&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">node</span> <span class="attr">name</span>=<span class="string">&quot;joint_state_publisher&quot;</span> <span class="attr">pkg</span>=<span class="string">&quot;joint_state_publisher&quot;</span> <span class="attr">type</span>=<span class="string">&quot;joint_state_publisher&quot;</span> &gt;</span><span class="tag">&lt;/<span class="name">node</span>&gt;</span> </span><br><span class="line"></span><br><span class="line">    <span class="comment">&lt;!-- 运行robot_state_publisher节点，发布tf  --&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">node</span> <span class="attr">name</span>=<span class="string">&quot;robot_state_publisher&quot;</span> <span class="attr">pkg</span>=<span class="string">&quot;robot_state_publisher&quot;</span> <span class="attr">type</span>=<span class="string">&quot;robot_state_publisher&quot;</span>  <span class="attr">output</span>=<span class="string">&quot;screen&quot;</span> &gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">param</span> <span class="attr">name</span>=<span class="string">&quot;publish_frequency&quot;</span> <span class="attr">type</span>=<span class="string">&quot;double&quot;</span> <span class="attr">value</span>=<span class="string">&quot;50.0&quot;</span> /&gt;</span></span><br><span class="line">    <span class="tag">&lt;/<span class="name">node</span>&gt;</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">&lt;!-- 在gazebo中加载机器人模型--&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">node</span> <span class="attr">name</span>=<span class="string">&quot;urdf_spawner&quot;</span> <span class="attr">pkg</span>=<span class="string">&quot;gazebo_ros&quot;</span> <span class="attr">type</span>=<span class="string">&quot;spawn_model&quot;</span> <span class="attr">respawn</span>=<span class="string">&quot;false&quot;</span> <span class="attr">output</span>=<span class="string">&quot;screen&quot;</span></span></span><br><span class="line"><span class="tag">          <span class="attr">args</span>=<span class="string">&quot;-urdf -model mbot -param robot_description&quot;</span>/&gt;</span> </span><br><span class="line"></span><br><span class="line"><span class="tag">&lt;/<span class="name">launch</span>&gt;</span></span><br></pre></td></tr></table></figure><h2 id="3-启动Gazebo仿真环境">3. 启动Gazebo仿真环境</h2><p>在终端中运行以下命令启动 Gazebo 仿真环境：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">roslaunch mbot_gazebo mygazebo.launch</span><br></pre></td></tr></table></figure><p>效果如下图所示：<br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/59ce4b406c659c2b3dd7e0001859e214.png" alt="gazebo仿真环境"></p><h2 id="4-启动RViz可视化工具">4. 启动RViz可视化工具</h2><p>在另一个终端中运行以下命令启动导航以及 rviz 可视化工具：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">roslaunch mbot_navigation exploring_slam_demo.launch</span><br></pre></td></tr></table></figure><p>效果如下图所示：<br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/cfbe608c3ae94cd003bdd00e1f2f265f.png" alt="rviz视图"></p><h2 id="5-启动自动导航建图功能">5.启动自动导航建图功能</h2><p>在另一个终端中运行以下命令启动自动导航建图功能：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">rosrun mbot_navigation exploring_slam.py</span><br></pre></td></tr></table></figure><p>效果如下图所示：<br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/07ea6886255a969c056227e00ca798bd.png" alt="自动导航"></p><h1>运行结果</h1><p>在 Gazebo 中运行自动导航建图功能后，机器人会在仿真环境中自主探索并构建地图。最终生成的地图可以在 RViz 中查看，效果如下图所示：<br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/2025/06/4e2fd5da46aa58000df0aabc03d9a5ed.png" alt=""></p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;项目概述&lt;/h1&gt;
&lt;p&gt;本大作业利用 ROS  和 Gazebo 仿真环境，实现了一个自主导航建图系统。项目包含以下核心功能：&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;在 Gazebo 中创建自定义仿真环境&lt;/li&gt;
&lt;li&gt;搭建移动机器人模型并配置传感器&lt;/li&gt;
&lt;li&gt;使用 g</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>创新实践作业</title>
    <link href="http://example.com/post/6179e16d.html"/>
    <id>http://example.com/post/6179e16d.html</id>
    <published>2025-05-30T05:39:20.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>Arduino简介</h1><p>Arduino是一款便捷灵活、方便上手的开源电子原型平台。包含硬件（各种型号的Arduino板）和软件（Arduino IDE)。由一个欧洲开发团队于2005年冬季开发。其特点有：<br>1、跨平台</p><p>Arduino IDE可以在Windows、Macintosh OS X、Linux三大主流操作系统上运行，而其他的大多数控制器只能在Windows上开发。<br>2、简单清晰</p><p>Arduino IDE基于processing IDE开发。对于初学者来说，极易掌握，同时有着足够的灵活性。<br>3、开放性</p><p>Arduino的硬件原理图、电路图、IDE软件及核心库文件都是开源的，在开源协议范围内里可以任意修改原始设计及相应代码。<br>4、编程方式多样代码简洁</p><p>Arduino编程主要有以下几种方式：第一种是使用官网Arduino IDE编程环境，这可以在官网下载，支持Windows，MacOS，Linux操作系统。第二如果不太喜欢写代码，或者是教小孩子玩Arduino，也有图形化的编程环境，比如Mixly/Scratch。</p><h1>传感器及舵机简介</h1><ol><li>雨滴传感器</li></ol><p>雨滴传感器主要是用来检测是否下雨及雨量的大小。主要用于汽车智能灯光（AFS）系统、汽车自动雨刷系统、智能车窗系统。雨滴传感器基本上是一块板，上面以线形形式涂覆镍。雨滴传感器常见的工作原理是通过检测水滴的导电性来判断是否下雨。它是利用两个电极之间的电导性变化来测量水滴的存在。</p><ol start="2"><li>超声波传感器</li></ol><p>超声波传感器是一种使用声波测量物体距离的设备。它的工作原理是发出超声波频率的声波并等待它从物体反弹回来。然后，使用声音传输和声音接收之间的时间延迟来计算距离。</p><ol start="3"><li>光敏电阻光照传感器</li></ol><p>光敏电阻是用硫化隔或硒化隔等半导体材料制成的特殊电阻器，其工作原理是基于内光电效应。随着光照强度的升高，电阻值迅速降，其在无光照时，几乎呈高阻状态，暗时电阻很大。光敏电阻模块一般用来检测周围环境的光线的亮度，触发单片机或继电器模块等。</p><ol start="4"><li>舵机</li></ol><p>舵机是一种位置（角度）伺服的驱动器。舵机只是一种通俗的叫法，其实质是一个伺服马达。在需要角度不断变化并可以保持的控制系统中应用广泛。如遥控机械人、飞机模型等。常见的舵机有两种，一种舵机轴可以旋转180度，还有一种舵机轴可以连续旋转。这种舵机的旋转速度是可以控制的。</p><h1>传感器应用实验</h1><ol><li>雨滴传感器应用实验</li></ol><p>将雨滴传感器的控制模块上的VCC连接到开发板的5V输出。<br>将雨滴传感器的控制模块上的GND连接到开发板的GND。<br>将雨滴传感器的控制模块上的AO连接到开发板上的A0模拟输入引脚。</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line">const int rainSensorPin = A0;</span><br><span class="line"></span><br><span class="line">void setup() &#123;</span><br><span class="line">    Serial.begin(9600);</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line">void loop() &#123;</span><br><span class="line">    int sensorValue = analogRead(rainSensorPin);</span><br><span class="line">    float voltage = sensorValue * (5.0 / 1023.0);</span><br><span class="line"></span><br><span class="line">    Serial.print(&quot;Voltage: &quot;);</span><br><span class="line">    Serial.println(voltage);</span><br><span class="line">  if (voltage &lt; 2):</span><br><span class="line">  &#123;</span><br><span class="line">    Serial.print(&quot;有雨滴&quot;);</span><br><span class="line"></span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">    delay(1000);</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><ol start="2"><li>超声波传感器应用实验</li></ol><p>将超声波传感器的VCC连接到开发板的5V输出。<br>将超声波传感器的Trig连接到开发板的9号数字输出针脚。<br>将超声波传感器的Echo连接到开发板的10号数字输入针脚。<br>将超声波传感器的GND连接到开发板的GND。</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><span class="line">const int trigPin = 9;</span><br><span class="line">const int echoPin = 10;</span><br><span class="line"> </span><br><span class="line">long duration;</span><br><span class="line">int distance;</span><br><span class="line"></span><br><span class="line">void setup() &#123;</span><br><span class="line">  Serial.begin(9600);</span><br><span class="line">  pinMode(trigPin, OUTPUT);</span><br><span class="line">  pinMode(echoPin, INPUT);</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line">void loop() &#123;</span><br><span class="line">  digitalWrite(trigPin, LOW);</span><br><span class="line">  delayMicroseconds(2);</span><br><span class="line"> </span><br><span class="line">  digitalWrite(trigPin, HIGH);</span><br><span class="line">  delayMicroseconds(10);</span><br><span class="line">  digitalWrite(trigPin, LOW);</span><br><span class="line"></span><br><span class="line">  duration = pulseIn(echoPin, HIGH);</span><br><span class="line">  distance = duration * 0.034 / 2;</span><br><span class="line"></span><br><span class="line">  Serial.print(&quot;Distance: &quot;);</span><br><span class="line">  Serial.println(distance);</span><br><span class="line"></span><br><span class="line">  delay(500);</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><ol start="3"><li>光敏电阻光照传感器应用实验</li></ol><p>将传感器的VCC端接开发板的5V供电；<br>将传感器的GND端接开发板的GND；<br>将传感器的AO（模拟信号输出端）接开发板的A0模拟输入引脚；</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line">int LDR_AO_Pin = A0; </span><br><span class="line">int LDRValue = 0; </span><br><span class="line">#define ADC_MAX_VALUE 1023 </span><br><span class="line"></span><br><span class="line">void setup() &#123;</span><br><span class="line">  Serial.begin(9600); </span><br><span class="line">  pinMode(LDR_AO_Pin, INPUT);</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line">void loop() &#123;</span><br><span class="line">  LDRValue = analogRead(LDR_AO_Pin); </span><br><span class="line">  Serial.print(&quot;光照强度: &quot;);</span><br><span class="line">  Serial.println(ADC_MAX_VALUE - LDRValue); </span><br><span class="line">  delay(1000); </span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><p>四、舵机应用实验</p><p>信号线（通常是橙色或黄色线）连接到开发板的9号PWM输出引脚。<br>电源线（红色线）连接到开发板的5V。<br>地线（棕色或黑色线）连接到开发板的GND。</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line">#include &lt;Servo.h&gt;</span><br><span class="line"></span><br><span class="line">Servo myservo;  </span><br><span class="line"></span><br><span class="line">void setup() &#123;</span><br><span class="line">  myservo.attach(9);  </span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line">void loop() &#123;</span><br><span class="line">  for (int pos = 0; pos &lt;= 180; pos += 1) &#123;</span><br><span class="line">    myservo.write(pos);             </span><br><span class="line">    delay(15);                      </span><br><span class="line">  &#125;</span><br><span class="line">  for (int pos = 180; pos &gt;= 0; pos -= 1) &#123;</span><br><span class="line">    myservo.write(pos);            </span><br><span class="line">    delay(15);                     </span><br><span class="line">  &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><p>五、综合应用实验</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br></pre></td><td class="code"><pre><span class="line">#include &lt;Servo.h&gt;  </span><br><span class="line"></span><br><span class="line">const int trigPin = 9;   </span><br><span class="line">const int echoPin = 10;  </span><br><span class="line">const int servoPin = 6;  </span><br><span class="line"></span><br><span class="line">Servo myServo;          </span><br><span class="line"></span><br><span class="line">void setup() &#123;</span><br><span class="line">  pinMode(trigPin, OUTPUT);</span><br><span class="line">  pinMode(echoPin, INPUT);</span><br><span class="line">  myServo.attach(servoPin);</span><br><span class="line">  </span><br><span class="line">  Serial.begin(9600);     </span><br><span class="line"></span><br><span class="line">void loop() &#123;</span><br><span class="line">  long duration;</span><br><span class="line">  int distance;</span><br><span class="line">  </span><br><span class="line">  digitalWrite(trigPin, LOW);</span><br><span class="line">  delayMicroseconds(2);</span><br><span class="line">  digitalWrite(trigPin, HIGH);</span><br><span class="line">  delayMicroseconds(10);</span><br><span class="line">  digitalWrite(trigPin, LOW);</span><br><span class="line">  </span><br><span class="line">  duration = pulseIn(echoPin, HIGH);</span><br><span class="line">  </span><br><span class="line">  distance = duration * 0.034 / 2;</span><br><span class="line">  </span><br><span class="line">  if (distance &gt; 40) distance = 40;</span><br><span class="line">  if (distance &lt; 0) distance = 0;</span><br><span class="line">  </span><br><span class="line">  int angle = map(distance, 0, 40, 0, 180);</span><br><span class="line">  </span><br><span class="line"></span><br><span class="line">  myServo.write(angle);</span><br><span class="line">  </span><br><span class="line">  </span><br><span class="line">  delay(100); </span><br><span class="line">&#125;</span><br><span class="line"></span><br></pre></td></tr></table></figure>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;Arduino简介&lt;/h1&gt;
&lt;p&gt;Arduino是一款便捷灵活、方便上手的开源电子原型平台。包含硬件（各种型号的Arduino板）和软件（Arduino IDE)。由一个欧洲开发团队于2005年冬季开发。其特点有：&lt;br&gt;
1、跨平台&lt;/p&gt;
&lt;p&gt;Arduino ID</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>机器人系统设计及其应用</title>
    <link href="http://example.com/post/d1f3a49a.html"/>
    <id>http://example.com/post/d1f3a49a.html</id>
    <published>2025-05-26T07:55:12.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>填空题</h1><h2 id="机器人系统组成与基本特征">机器人系统组成与基本特征</h2><ol><li>工业机器人系统一般包括<strong>机械系统、驱动系统、控制系统</strong>三个基本组成部分。</li><li>机器人本体也称<strong>操作机</strong>。它是用来完成各种作业任务的执行机构，主要由<strong>机械臂</strong>、驱动与传动装置以及<strong>传感器</strong>三大部分组成。</li><li>工业机器人基本特征一般是指机器人的<strong>应用范围</strong>、机器人的<strong>技术特征</strong>或机器人的<strong>特有功能</strong>等。</li><li><strong>工作半径</strong>作为工业机器人的基本特征参数时,表示工业机器人的工作范围。</li><li>由于<strong>重复定位精度</strong>不受工作载荷变化的影响,故通常将其作为衡量示教再现工业机器人水平的重要指标。</li></ol><h2 id="机器人结构与分类">机器人结构与分类</h2><ol start="6"><li>关节型机器人主要由<strong>回转</strong>和旋转自由度构成。从肘到手臂根部的部分称为<strong>上臂</strong>，从肘到手腕的部分称为<strong>前臂</strong>。</li><li>极坐标型机器人,具有<strong>平移、旋转</strong>和摆动三个自由度,动作空间形成<strong>球面</strong>的一部分。</li><li>臂部按运动和布局、驱动方式、传动和导向装置可分为<strong>伸缩型</strong>臂部结构，<strong>转动伸缩型</strong>臂部结构，<strong>驱伸型</strong>臂部结构，机械传动臂部结构四种结构类型。</li><li>按手臂的运动形式,可分为<strong>直线运动型</strong>臂部结构、<strong>回转运动型</strong>臂部结构和<strong>复合运动型</strong>臂部结构等三种类型。</li><li>臂部按手臂的结构形式，可分为<strong>单臂式臂部结构、双臂式臂部结构和悬挂式臂部结构</strong>等三类。</li><li>多关节型机器人根据摆动方向的不同,可分为<strong>垂直</strong>多关节机器人和<strong>水平</strong>多关节机器人两种类型。</li><li>按照工业机器人的机械结构可以分为:串联结构、<strong>并联结构</strong>和<strong>混合结构</strong>三种。</li><li>直角坐标机器人具有空间上相互垂直的多个直线移动轴,通常为<strong>3</strong>个轴,一般动作空间为一个<strong>长方体</strong>。</li></ol><h2 id="机器人驱动与传动">机器人驱动与传动</h2><ol start="14"><li>两种常用的机器人关节减速器包括<strong>RV减速器和谐波减速器</strong>。</li><li>谐波齿轮减速器通常由3个基本构件组成，包括一个有内齿的<strong>刚轮</strong>，一个带有外齿的<strong>柔轮</strong>和一个<strong>波形发生器</strong>。</li><li>臂部回转运动的驱动力矩应根据启动时产生的<strong>惯性力矩</strong>与回转部件支承处的<strong>摩擦力矩</strong>来计算。</li><li>手臂作水平伸缩运动时，需要克服<strong>摩擦阻力</strong>和启动过程中的<strong>惯性力</strong>。</li><li><strong>交叉滚子轴承</strong>和<strong>薄壁轴承</strong>是工业机器人的应用中较为主要的两类轴承。</li><li>工业机器人采用电动驱动方式时,经常使用的电机包括<strong>交流伺服电动机、直流伺服电动机、步进带电动机</strong>。</li><li>液压驱动系统通常是由<strong>液压传动系统和液压控制系统</strong>所组成。</li><li>工业机器人伺服系统包括<strong>伺服驱动器和伺服电机</strong>。</li><li>对于工业机器人来说,操作机结构的重要元件是执行机构的<strong>导轨和支撑</strong>。</li><li>工业机器人驱动系统主要指<strong>机械系统</strong>的驱动装置,它用以使<strong>执行机构</strong>产生相应的动作。</li></ol><h2 id="机器人控制系统">机器人控制系统</h2><ol start="24"><li><strong>控制系统</strong>的任务是根据机器人的作业指令程序及从<strong>传感器</strong>反馈回来的信号来控制机器人的执行机构,使其完成规定的运动和功能。</li><li>工业机器人的控制装置是由<strong>控制器、驱动装置、测量系统</strong>等组成。</li><li>工业机器人的<strong>程序控制装置</strong>是指可通过编制软件程序来实现柔性控制操作的装置。</li><li>主控制计算机关键作用是负责机器人<strong>运动学的计算、轨迹规划</strong>等,这部分对实时性要求非常高,是系统可靠运行的关键。</li><li>控制器软件系统分为三个层次,分别是:<strong>硬件驱动层、核心层、应用层</strong>。</li><li>机器人控制系统按其控制方式可分为<strong>集中控制系统、主从控制系统和分散控制系统</strong>。</li><li>工业机器人的控制系统由<strong>硬件电路</strong>系统和<strong>软件</strong>系统两部分组成。</li><li>工业机器人的<strong>控制系统</strong>是机器人的重要组成部分,用于对操作对象的控制,以完成特定的工作任务。</li></ol><h2 id="机器人语言与示教">机器人语言与示教</h2><ol start="32"><li>机器人语言按照作业描述水平的高低可以分为三类:<strong>动作级、对象级、任务级</strong>。</li><li>为使机器人完成规定的任务，在工作前由操作者把作业要求的内容预先教给机器人，进行这种操作称为<strong>示教</strong>。把示教的内容保存下来称为<strong>记忆</strong>。使机器人按示教的内容动作称为<strong>再现</strong>。</li><li>在线示教可以通过<strong>手动牵引的直觉示教、基于多传感器融合的示教和基于人工演示的直觉示教</strong>等方法完成。</li></ol><h2 id="坐标系与运动模式">坐标系与运动模式</h2><ol start="35"><li>目前常用的机器人坐标系形式主要包括:<strong>基坐标系、大地坐标系、工件坐标系、工具坐标系</strong>等。</li><li>工件坐标系拥有两个框架:<strong>用户框架</strong>和<strong>工件框架</strong>。</li><li>机器人运动模式包括:<strong>单轴运动模式、线性运动模式、重定位运动模式</strong>。</li></ol><h2 id="末端执行器与手部">末端执行器与手部</h2><ol start="38"><li>机器人末端执行器中，控制阀将来自气泵的压缩空气自喷嘴通入，形成高速射流，将吸盘内腔中的空气带走而形成负压，使吸盘吸住物体称为<strong>气流负压式吸盘</strong>。</li><li>机器人末端执行器中，利用电磁控制阀将吸盘与真空泵相联，当抽气时，吸盘腔内的空气被抽出，形成负压而吸住物体的称为<strong>真空泵排气式吸盘</strong>。</li><li>机器人末端执行器中，靠向下挤压力将吸盘内的空气排出，使其内部形成负压，将工件吸住称为<strong>挤压排气式吸盘</strong>。</li><li>根据工业机器人手部的夹持原理，一般可以分为<strong>手指</strong>式和吸盘式两大类。</li><li>磁力吸附式手部在手部装上电磁铁，通过磁场吸力把工件吸住，又分为<strong>电磁</strong>吸盘和<strong>永磁</strong>吸盘两种。</li><li>根据工业机器人手部的智能程度可以分为普通式手部和<strong>智能式</strong>手部。</li><li>机器人<strong>手臂</strong>的主要作用是支承手部和腕部,并改变末端执行器在空间的位置。</li></ol><h2 id="传感器与测量">传感器与测量</h2><ol start="45"><li>测量直线位移的直线位移传感器有<strong>电位计式传感器</strong>和<strong>可调变压器</strong>两种。</li></ol><h2 id="其他">其他</h2><ol start="46"><li><strong>行程开关</strong>是根据运动部件的行程位置进行切换电路的电气装置,起到控制机械装备的行程和限位保护作用。</li></ol><h1>名词解释</h1><ol><li>工业机器人承载能力</li></ol><p>工业机器人承载能力是指机器人在作业范围内的任何位姿上所能承受的最大重量。</p><ol start="2"><li>工业机器人作业范围</li></ol><p>工业机器人作业范围是指机器人运动时手臂末端或手腕中心所能达到的位置点的集合。</p><ol start="3"><li>位姿</li></ol><p>机器人系统在管理和操作机器人时,其末端执行机构必须处于合适的空间位置和姿态,简称位姿。</p><ol start="4"><li>工作范围</li></ol><p>是指机器人手臂末端或手腕中心所能到达的所有点的集合。</p><ol start="5"><li>定位精度</li></ol><p>指机器人末端执行器的实际位置与目标位置之间的偏差。</p><ol start="6"><li>冗余自由度</li></ol><p>大于6个的自由度称为冗余自由度。冗余自由度增加了机器人的灵活性，可方便机器人避开障碍物和改善机器人的动力性能。</p><ol start="7"><li>伺服控制</li></ol><p>指对物体运动的位置、速度及加速度等变化量的有效控制。这种控制已在各领域得到普及。</p><ol start="8"><li>当量夹紧力</li></ol><p>把质量为m的工件，按某一方位夹紧，其拉紧油缸具有的最小驱动力所产生的夹紧力，称为工件在这个方位的当量夹紧力。</p><ol start="9"><li>操作机</li></ol><p>具有和人手臂相似的动作功能，可在空间抓放物体或进行其它操作的机械装置</p><ol start="10"><li>精度</li></ol><p>是一个位置量相对于其参照系的绝对度量，指机器人手部实际到达位置与所需要到达的理想位置之间的差距。</p><ol start="11"><li>并联机器人</li></ol><p>并联机构作为其结构形式的机器人称为并联机器人。</p><ol start="12"><li></li></ol><p>重复定位精度</p><p>指重复定位精度是指机器人重复到达某一目标位置的差异程度。它是衡量一系列误差值的密集程度,即重复度。</p><h1>简答题</h1><h3 id="1-请说明真空吸附式手部系统设计的关键问题有哪些？">1. 请说明真空吸附式手部系统设计的关键问题有哪些？</h3><p>（1）真空源的选择</p><pre><code>真空源是真空系统的“心脏”部分，分为真空泵和真空发生器。空泵是比较常用的真空源，其结构和工作原理与空气压缩机相似，不同的是真空泵的进气口是负压，排气口是大气压。直空发生器是一种新型真空源，以压缩空气为动力源，利用在文丘里管中流动、喷射的高速气体对周围气体的卷吸作用来产生真空。</code></pre><p>（2）吸盘的结构</p><pre><code>吸盘按结构可分为普通型与特殊型两大类。普通型吸盘一般用来吸附表面光滑平整的工件。普通型吸盘橡胶部分的形状一般为碗状。吸盘的形状可分为长方形、圆形和圆弧形。特殊型吸盘是为了满足特殊应用场合而专门设计的。</code></pre><p>（3）吸盘的吸附能力</p><pre><code>真空吸附技术以大气压为作用力，通过真空源抽出一定量的气体分子，使吸盘与工件形成的密闭容积内压力降低，从而使吸盘的内外形成压力差。在这个压力差的作用下，吸盘被压向工件，从而把工件吸起。</code></pre><h3 id="2-试说明普通丝杠驱动和滚珠丝杠驱动在运动方式及特点方面的区别。">2. 试说明普通丝杠驱动和滚珠丝杠驱动在运动方式及特点方面的区别。</h3><p>(1)普通丝杠驱动</p><p>运动方式:一个旋转的精密丝杠驱动一个螺母沿丝杠轴向移动</p><p>特点:摩擦力较大,效率低,惯性大,易出现爬行现象,精度低,回差大</p><p>应用:低成本工业机器人</p><p>(2)滚珠丝杠驱动</p><p>运动方式:装有循环球的螺母通过与丝杠的配合来将旋转运动转换成直线运动</p><p>特点:容易与线性轴匹配</p><h3 id="3-用于工业机器人的滚珠导轨及滚柱导轨形式主要有哪些-在应用方面有何区别">3. 用于工业机器人的滚珠导轨及滚柱导轨形式主要有哪些,在应用方面有何区别?</h3><p>(1)带循环滚子的滚柱导轨</p><p>这种滚动支承可用于操作机执行机构的直线位移导轨上,它具有较高的接触刚度、耐久性、低摩擦系数和较高的位移精度。</p><p>(2)带滚珠的活动托架-轨道式滚动导轨</p><p>导轨的结构特点是滚珠与具有特殊纵向槽的固定轨道间是线接触。同时能产生预紧力,增加了作用在导轨上的许用载荷,提高了耐久性。棱柱形导轨能承受垂直的、水平横向的、弯曲的及扭转形式的载荷。</p><p>(3)带滚珠轴套式线性滚动导轨</p><p>导轨滑杆为圆柱形截面并带有纵向槽,滚珠可在槽中滚动。安装滚珠时相对于轴套加有预紧力。在导轨滑杆运动时,为使滚珠返回,在轴套体上开槽。</p><h3 id="4-说明电磁铁与永久磁铁作为吸盘时，在取下工件时有何区别？">4. 说明电磁铁与永久磁铁作为吸盘时，在取下工件时有何区别？</h3><p>电磁吸盘一旦断电，电磁吸力即消失，工件因此被松开；若采用永久磁铁作为吸盘，则必须强制性取下工件。</p><h3 id="5-导向装置一般根据臂部的安装形式，具体的结构及抓取重量等因素来确定。目前常见的导向装置包括哪三类？">5. 导向装置一般根据臂部的安装形式，具体的结构及抓取重量等因素来确定。目前常见的导向装置包括哪三类？</h3><p>1)导向杆（单导向杆、双导向杆、四柱导向杆等）式</p><p>2)键（单键、花键）式</p><p>3)导轨（矩形导轨、V型导轨、燕尾导轨等）式。</p><h3 id="6-试述典型工业机器人控制器的组成及各部分功能。">6. 试述典型工业机器人控制器的组成及各部分功能。</h3><p>典型的工业机器人控制器采用多CPU计算机结构,分为主控制计算机、数字位置伺服控制卡和编程示教盒等。</p><p>(1)主控制计算机完成机器人的运动规划、插补和主控逻辑、数字1/0以及通信联网等功能;</p><p>(2)数字位置伺服控制卡完成机器人的位置运动控制;</p><p>(3)编程示教器则实现机器人控制器的人机交互功能。</p><h3 id="7-说明目前常用的工业机器人的坐标形式及特点。">7. 说明目前常用的工业机器人的坐标形式及特点。</h3><p>(1)基坐标系:基坐标系在机器人中的基座中有相应的零点,使用该方式,机器人的移动具有可预测性,对于将机器人从一个位置移动到另一个位置时很有帮助。</p><p>(2)大地坐标系:大地坐标系在工作单元或工作站中的固定位置均有其相应的零点。默认情况下,大地坐标系与基坐标系是一致的。</p><p>(3)工件坐标系:工件坐标系是拥有特定附加属性的坐标系。主要功能是简化编程,工件坐标系拥有两个框架:用户框架和工件框架。</p><p>(4)工具坐标系:工具坐标系将工具中心点(TCP)设为零点,由此定义工具的位置和方向。执行程序时,机器人就是将TCP移至编程位置。如果要更改工具,机器人的移动也将随之改变,以便新的TCP可以到达目标。</p><h3 id="8-简述机器人手臂的特点。">8. 简述机器人手臂的特点。</h3><p>（1）2-3个自由度</p><p>即伸缩、回转、俯仰(或升降)，而专用机械手的臂部一般有1~2个自由度，为伸缩、回转和直行。</p><p>（2）重量大，受力复杂</p><p>在运动时，直接承受腕部、手部和工件（或工具）的动、静载荷，特别是高速运动时，将产生较大的惯性力，引起冲击，影响定位的准确性。</p><p>（3）安装在机身上</p><p>工业机器人的臂部一般与控制系统和驱动系统一起安装在机身上。</p><h3 id="9-图示为丝杆螺母传动的手臂升降机构-试述其工作原理及特点。">9. 图示为丝杆螺母传动的手臂升降机构,试述其工作原理及特点。</h3><p><img src="https://ce-images.oss-cn-beijing.aliyuncs.com/school_9887/course_64528/c4701e12d002dd5e2cb6cca6f27ad32849dd42c1.png" alt=""></p><p>如图所示为采用丝杠螺母传动的手臂升降机构。由电动机1带动蜗杆2使涡轮5回转,依靠涡轮内孔的螺纹带动丝杠4作升降运动。为了防止丝杠的转动,在丝杠上端铣有花键与固定在箱体6上的花键套7组成导向装置。</p><h3 id="10-试说明机器人的哪些基本参数决定了工业机器人的工艺性和结构特点">10. 试说明机器人的哪些基本参数决定了工业机器人的工艺性和结构特点?</h3><p>(1)承载能力;</p><p>(2)动作自由度;</p><p>(3)工作空间的外形和尺寸;</p><p>(4)定位误差;</p><p>(5)控制系统形式。</p><h3 id="11-叙述说明机器人关节减速器的特点及作用。">11. 叙述说明机器人关节减速器的特点及作用。</h3><p>(1)特点:传动链短、体积小、功率大、质量轻和易于控制等。<br>(2)作用:使机器人伺服电动机在一个合适的速度下运转并精确地将转速降到工业机器人各部分需要的速度,在提高机械本体刚性的同时输出更大的转矩。</p><h3 id="12-钳爪式手部按照夹取方式的不同，可以分为哪两种类型，并说明两者的主要区别。">12. 钳爪式手部按照夹取方式的不同，可以分为哪两种类型，并说明两者的主要区别。</h3><p>答：钳爪式手部按照夹取方式的不同，可分为内撑式和外夹式两种。内撑钳爪式手部和外夹钳爪式手部的主要区别在于夹持工件或工具的部位不同，夹持时手部动作的方向相反。</p><h3 id="13-工业机器人的电驱动需要计算的内容包括哪些-。">13. 工业机器人的电驱动需要计算的内容包括哪些?。</h3><p>(1)电机功率;(2)电机扭矩;(3)电机转速;(4)减速机减速比;(5)电机惯量/负载惯量的匹配关系。</p><h3 id="14-说明直角坐标机器人、圆柱坐标机器人和球坐标机器人三种类型的机器人各自的特点">14. 说明直角坐标机器人、圆柱坐标机器人和球坐标机器人三种类型的机器人各自的特点?</h3><p>(1)直角坐标型机器人结构简单、刚性好,但缺点是在机器人动作范围内,必须有沿轴线前后方向的移动空间,空间利用率较低。</p><p>(2)圆柱坐标机器人结构简单,定位精度高,空间轨迹易于求解;动作范围相对较小,设备的空间因数较低。</p><p>(3)球坐标机器人结构紧凑,所占空间体积小于直角坐标和柱面坐标机器人。</p><h3 id="15-试说明钳爪式手部由哪几部分结构组成？">15. 试说明钳爪式手部由哪几部分结构组成？</h3><p>（1）手指（手爪）；</p><p>（2）驱动机构；</p><p>（3）传动机构；</p><p>（4）连接元件；</p><p>（5）支承元件；</p><h3 id="16-选择工业机器人执行机构的电驱动装置时需要满足哪些条件">16. 选择工业机器人执行机构的电驱动装置时需要满足哪些条件?</h3><p>(1)在最大加速度情况下,启动速度快。</p><p>(2)在过渡工作状态下,电流或力矩的过载能力强。</p><p>(3)功率大,损耗少。</p><p>(4)调节速度范围大。</p><h3 id="17-试述工业机器人和操作机的区别。">17. 试述工业机器人和操作机的区别。</h3><p>工业机器人是一种能自动控制、可重复编程、多功能、多自由度的操作机,能搬运材料、工件或挟持工具,用以完成各种作业;</p><p>操作机具有和人手臂相似的动作功能,是一种可在空间抓放物体或进行其它操作的机械装置。</p><h3 id="18-试述典型工业机器人控制器的组成及各组成部分之间的通信方式。">18. 试述典型工业机器人控制器的组成及各组成部分之间的通信方式。</h3><p>典型的工业机器人控制器采用多CPU计算机结构,分为主控制计算机、数字位置伺服控制卡和编程示教盒等。</p><p>主计算机和编程示教器可通过串口进行异步通信,主计算机和数字位置伺服控制卡实现实时通信,传递运动控制信息。</p><h3 id="19-按照作业描述水平的高低可以将机器人语言分为哪几种类型-有何区别">19. 按照作业描述水平的高低可以将机器人语言分为哪几种类型,有何区别?</h3><p>机器人语言按照作业描述水平的高低可以分为三类:动作级、对象级和任务级。</p><p>(1)动作级语言一般以机器人的动作行为为描述中心,由一系列命令组成,一般一个命令对应一个动作,语言简单,易于编程,但是不能进行复杂的数学运算;</p><p>(2)对象级语言是以描述操作物之间的关系为中心的操作语言。</p><p>(3)任务级语言是比较高级的机器人语言,只要按照某种原则给出最初的环境模型和最终的工作状态,机器人可自动进行推理计算,生成机器人的动作。</p><h3 id="20-试说明滚珠丝杠内循环与外循环两种循环方式的区别。">20. 试说明滚珠丝杠内循环与外循环两种循环方式的区别。</h3><p>(1)内循环</p><p>内循环方式的滚珠在循环过程中始终与丝杠表面保持接触。</p><p>(2)外循环</p><p>外循环方式中的滚珠在循环返向时,离开丝杠螺纹滚道,在螺母体内或体外作循环运动。</p><h3 id="21-为什么串联机器人在进行结构设计时需要进行刚度设计-提高机器人刚度可以采取哪些措施">21. 为什么串联机器人在进行结构设计时需要进行刚度设计?提高机器人刚度可以采取哪些措施?</h3><p>对于工业机器人操作机来说,大多为串联型多关节结构。在这种结构下,机器人操作机是一个多关节、多自由度的复杂机械装置,当受到外力作用时,执行器坐标原点就会产生一个小的位移偏差,偏差量的大小不仅与外力的大小、方向和作用点有关,而且还与执行机构末端所处的位置和姿态有关,这就是机器人的刚度。串联机器人的结构较弱,刚度较小等问题成为影响其末端定位精度及加工动态性能的首要因素。</p><p>提高刚度的措施:</p><p>(1)悬臂尽量短,拉伸压缩轴用实心轴,扭转轴用空心轴,并控制连接间隙;</p><p>(2)采用矩形截面的小臂结构设计,保障具备更高的抗拉、抗扭、抗弯曲性能。</p><h3 id="22-试述机器人转动机构的设计流程。">22. 试述机器人转动机构的设计流程。</h3><p>转动机构设计流程的内容包括运动性能、力学特性、机械结构、精度要求、详细设计、验证与修改等。</p><p>(1)方案制定</p><p>明确转动机构在机器人整机中的作用及位置,制定转动机构的方案。</p><p>(2)运动性能及参数</p><p>确定机器人转动机构的运动性能及参数要求,绘制转动机构的传动链或运动原理简图。</p><p>(3)力学特性</p><p>针对转动机构的设计对象,制定满足其结构的力学特性与参数。对转动机构的关键零部件还应进行强度、刚度、稳定性等计算。</p><p>(4)零部件建模与设计</p><p>在满足运动性能计算、力学特性分析的前提下,进行转动机构的零部件建模与设计。该设计应包括关键转动零件的设计,也应包括部分零件、部件的详细设计、优化设计等。</p><p>(5)精度要求</p><p>在转动机构的零部件结构设计时,必须考虑选用件的匹配及零部件间的配合,也包括传动误差分析,以满足精度要求。</p><p>(6)详细设计、验证与修改</p><p>在上述基础上进行转动机构及全部零部件的详细设计。验证转动机构的运动性能、力学特性及精度要求,修改零件的机械结构,直至满足各项技术要求。</p><h3 id="23-吸附式手部的主要工作原理是什么？根据吸附力的不同可以分为哪几种，其主要区别有哪些？">23. 吸附式手部的主要工作原理是什么？根据吸附力的不同可以分为哪几种，其主要区别有哪些？</h3><p>（1）吸附式手部主要靠吸附力来控制工件；</p><p>（2）根据吸附力的不同可以分为磁力吸附式和真空吸附式两种。</p><p>（3）区别：</p><p>磁力吸附式在手部上安装电磁铁，通过磁场吸力把工件吸住。只能吸住由铁磁料制成的工件，且被吸取过的工件上会有剩磁，只适用于工件对磁性要求不高的场合。</p><p>真空式吸附式用于搬运体积大、重量轻、易碎等的物体，在工业自动化生产中得到了广泛应用。</p><h3 id="24-试述机器人手臂机构的设计流程。">24. 试述机器人手臂机构的设计流程。</h3><p>手臂机构设计流程的内容包括运动性能、力学特性、机械结构、精度要求、详细设计、验证与修改等。</p><p>(1)方案制定</p><p>明确手臂机构在机器人整机中的作用及位置,制定手臂机构的方案。</p><p>(2)运动性能及参数</p><p>确定机器人手臂机构的运动性能及参数要求,绘制手臂机构的传动链和运动原理简图。</p><p>(3)力学特性</p><p>针对手臂机构的设计对象,制定满足其结构的力学特性与参数。对手臂机构的关键零部件还应进行强度、刚度、稳定性等计算。</p><p>(4)零部件建模与设计</p><p>在满足运动性能计算、力学特性分析的前提下, 进行手臂机构的零部件建模与设计。该设计应包括手臂关键零件及专用零部件的详细设计、优化设计等。</p><p>(5)精度要求</p><p>在手臂机构的零部件结构设计时,必须考虑选用件的匹配及零部件间的配合,也包括传动误差分析,以满足精度要求。</p><p>(6)工作节拍</p><p>针对机器人作业任务,按照工作顺序设计不同时间的节拍。</p><p>(7)详细设计、验证与修改</p><p>在上述基础上进行手臂机构及全部零部件的详细设计。验证手臂机构的运动性能、力学特性及精度要求,修改零件的机械结构,直至满足各项技术要求。</p><h3 id="25-试述机器人升降机构的设计流程。">25. 试述机器人升降机构的设计流程。</h3><p>升降机构设计流程的内容包括运动性能、力学特性、机械结构、精度要求、详细设计、验证与修改等。</p><p>(1)方案制定</p><p>明确升降机构在机器人整机中的作用及位置,制定升降机构的方案。</p><p>(2)运动性能及参数</p><p>确定机器人升降机构的运动性能及参数要求,绘制升降机构的传动链和运动原理简图。</p><p>(3)力学特性</p><p>针对升降机构的设计对象,制定满足其结构的力学特性与参数。对升降机构的关键零部件还应进行强度、刚度、稳定性等计算。</p><p>(4)零部件建模与设计</p><p>在满足运动性能计算、力学特性分析的前提下, 进行升降机构的零部件建模与设计。该设计应包括关键传动零件的设计,也应包括部分零件、部件的详细设计、优化设计等。</p><p>(5)精度要求</p><p>在升降机构的零部件结构设计时,必须考虑选用件的匹配及零部件间的配合,也包括传动误差分析,以满足精度要求。</p><p>(6)详细设计、验证与修改</p><p>在上述基础上进行升降机构及全部零部件的详细设计。验证升降机构的运动性能、力学特性及精度要求,修改零件的机械结构,直至满足各项技术要求。</p><h3 id="26-试说明谐波齿轮减速器的工作原理及特点。">26. 试说明谐波齿轮减速器的工作原理及特点。</h3><p>谐波齿轮减速器的波发生器装入柔轮后,迫使柔轮的剖面由原先的圆形变成椭圆形,当波发生器沿某一方向连续转动时,柔轮的变形不断改变,使柔轮与刚轮的啮合状态也不断改变,啮入—啮合—啮出—脱开—再啮入……,周而复始地进行,柔轮的外齿数少于刚轮的内齿数,从而实现柔轮相对刚轮沿发生器相反方向的缓慢旋转。</p><p>特点:</p><p>(1)结构简单,体积小,重量轻;</p><p>(2)传动比范围大;</p><p>(3)谐波齿轮减速器在啮合中其齿侧间隙可以调整,传动的回差很小,而且谐波齿轮减速器的高、低速轴位于同一轴线上,同轴性好,可实现高增速运动。与普通减速器相比,谐波齿轮减速器使用的材料要少50%,因此其体积及重量至少减少1/3,具有高精度、高承载力等优点。</p><p>(4)运动平稳,无冲击,噪声小。</p><p>(5)传动效率高,可实现高增速运动。</p><p>(6)可实现差速传动。</p><h3 id="27-机器人的作业示教的信息分为哪几种-分别描述哪些信息">27. 机器人的作业示教的信息分为哪几种,分别描述哪些信息?</h3><p>(1)位置与姿态信息:描述机器人动作路径和定位点的信息。</p><p>(2)顺序信息:描述机器人的动作顺序信息和机器人与周边装置的同步关系。</p><p>(3)动作与作业条件信息:描述机器人动作的速度、加速度以及作业条件。</p><h3 id="28-试写出五种机器人转动机构中常用的传动方式。">28. 试写出五种机器人转动机构中常用的传动方式。</h3><p>(写出其中五种即可)</p><p>(1)齿轮传动</p><p>(2)带传动</p><p>(3)链传动</p><p>(4)绳传动</p><p>(5)谐波减速器传动</p><p>(6)摆线针轮传动</p><p>(7)蜗杆减速器传动</p><h3 id="29-说明工业机器人伺服控制系统的组成及各部分功能。">29. 说明工业机器人伺服控制系统的组成及各部分功能。</h3><p>工业机器人伺服控制系统一般是由给定环节、测量环节、比较环节、放大运算环节和执行环节所组成。</p><p>(1)给定环节:是给出输入信号的环节,用于确定被控制对象的“目标值”(或称为给定值),给定环节可以用各种形式(电量、非电量、数字量、模拟量等)发出信号。</p><p>(2)测量环节:用于测量被控量,并把被控制量转换为便于传送的另外一个物理量。</p><p>(3)比较环节:它是将输人信号与测量环节测量的被控制量的反馈量相比较,得到偏差信号,包括幅值比较、相位比较和位移比较等。</p><p>(4)放大运算环节:是控制器的运算功能的实现,对偏差信号进行必要运算,然后进行功率放大,推动执行环节。</p><p>(5)执行环节:接收放大运算环节送来的控制信号,驱动被控制对象按照预期的规律运行。</p><h3 id="30-试述工业机器人手腕的定义及其功能。">30. 试述工业机器人手腕的定义及其功能。</h3><p>答：手腕是联接手臂和末端执行器的部件，其功能是通过机械接口连接并支撑末端执行器，在手臂和机座实现了末端执行器在作业空间的三个位置坐标（自由度）的基础上，再由手腕来实现末端执行器在作业空间的三个姿态（方位）坐标，即实现三个旋转自由度。</p><p>通常腕能实现绕空间三个坐标轴的转动，即回转运动、左右偏摆运动和俯仰运动。当有特殊需要时，还可以实现小距离的横移运动。手腕的自由度愈多，结构和控制愈复杂。因此，应根据机器人的作业要求来决定其应具有的自由度数目。在多数情况下，手腕具有一两个自由度即可满足作业要求。</p><h3 id="31-试述机器人在线示教与离线示教的方法及各自的特点。">31. 试述机器人在线示教与离线示教的方法及各自的特点。</h3><p>(1)在线示教是由技术人员引导,控制机器人运动,记录机器人作业的程序点并插人所需的机器人命令来完成程序的编制。其操作简单直观,技术人员在现场根据实际情况进行编程,基本上无需过多更改,错误率低,但编程效率低,难以满足频繁改变任务的场合。</p><p>(2)离线示教是指脱离机器人和实际的工作环境,通过计算机对机器人进行离线的编程,技术人员不对机器人实体进行控制,是在离线编程系统中进行编程或在模拟环境中进行仿真,生成示教数据,常用于工作人员对工作环境比较熟悉,所建立的3D模型能真实反映机器人的实际工作状态。此方法方便技术工作人员进行脱离实际的机器人示教,便于和CAD/CAM相结合,进而与机器人系统生成一体化操作,但对技术人员的技术水平要求高,实现也较在线示教复杂。</p><h3 id="32-机器人钳爪式手部机构的选择要求有哪些？">32. 机器人钳爪式手部机构的选择要求有哪些？</h3><p>（1）应具有足够的夹紧力；</p><p>（2）应具有足够的张开角；</p><p>（3）应能保证工件的可靠定位；</p><p>（4）应具有足够的强度和刚度；</p><p>（5）应适应被抓取对象的要求；</p><p>（6）尽可能具有一定的通用性 ；</p><h3 id="33-写出工业机器人的三种主要驱动方式及其各自的应用特点。">33. 写出工业机器人的三种主要驱动方式及其各自的应用特点。</h3><p>工业机器人驱动方式主要有:液压式、气动式和电动式。</p><p>(1)液压驱动</p><p>适用于承载能力大,惯量大以及在防焊环境中工作的机器人。但液压系统需进行能量转换,速度控制多数情况下采用节流调速,效率比电动驱动系统低。</p><p>(2)气动驱动具有速度快、系统结构简单、维修方便、价格低等特点。适用于中、小负荷的机器人。但因难于实现伺服控制,多用于程序控制的机械人中,如在冲压机器人。</p><p>(3)电动驱动</p><p>由于具备低惯量,大转矩的优点,交、直流伺服电机及其配套的伺服驱动器被广泛采用,电动驱动系统在机器人中被大量应用。该类系统不需能量转换,使用方便,控制灵活。</p><h3 id="34-机器人手臂直线运动包括哪几种类型-实现手臂往复直线运动的机构有哪些-写出其中的四种">34. 机器人手臂直线运动包括哪几种类型?实现手臂往复直线运动的机构有哪些,写出其中的四种?</h3><p>机器人手臂的伸缩、升降及横向(或纵向)移动均属于直线运动。</p><p>实现手臂往复直线运动的机构:</p><p>(1)活塞液压(气)缸;</p><p>(2)活塞缸和齿轮齿条机构;</p><p>(3)丝杠螺母机构;</p><p>(4)活塞缸和连杆机构。</p><h3 id="35-图示为带环形柔轮的外啮合复波式谐波传动机构-试述其工作原理及特点。">35. 图示为带环形柔轮的外啮合复波式谐波传动机构,试述其工作原理及特点。</h3><p><img src="https://ce-images.oss-cn-beijing.aliyuncs.com/school_9887/course_64528/7b6a685b8342db23b98bc69c58264ac8b9e2ac99.png" alt=""></p><p>图示为外啮合复波式谐波传动原理简图。图中H为波发生器,G1为第一级固定刚轮,G2为第二级输出的活动刚轮,R1和R2为固连在一宽柔轮上的两个柔轮齿圈,在宽度上分别与刚轮G2和G1啮合。于是,波发生器H、柔轮R2和刚轮G2组成第一级谐波减速传动(波发生器主动,刚轮固定,柔轮从动)。而波发生器H、柔轮R2和刚轮G2组成第二级谐波减速传动(波发生器主动,柔轮相对固定,刚轮从动)。</p><p>复波式谐波齿轮传动使用于大传动比、高精度的减速装置中。其特点是结构简单、传动比范围大,精度高,但齿间磨损较大,传动效率约为65%。</p><h3 id="36-简述机器人控制器软件系统的基本功能。">36. 简述机器人控制器软件系统的基本功能。</h3><p>(1)记忆功能</p><p>(2)示教功能</p><p>(3)与外围设备联系功能</p><p>(4)坐标设置功能</p><p>(5)人机接口模块输人输出功能</p><p>(6)传感器模块感知功能</p><p>(7)位置伺服功能</p><p>(8)故障诊断安全保护功能</p><p>(9)控制总线传输功能</p><p>(10)编程方式</p><h3 id="37-机器人结构设计时为什么要进行刚度设计？写出三种提高机器人刚度的措施？">37. 机器人结构设计时为什么要进行刚度设计？写出三种提高机器人刚度的措施？</h3><p>工业机器人操作机大多为串联型多关节结构，是一个多关节、多自由度的复杂机械装置，当受到外力作用时，执行器坐标原点就会产生一个小的位移偏差，偏差量的大小不仅与外力的大小、方向和作用点有关，而且还与执行机构末端所处的位置和姿态有关，所以在进行机器人结构设计时需要进行刚度设计。</p><p>提高刚度的措施：</p><p>悬臂尽量短，拉伸压缩轴用实心轴，扭转轴用空心轴，并控制连接间隙；</p><p>采用矩形截面的小臂结构设计，保障具备更高的抗拉、抗扭、抗弯曲性能。</p><h3 id="38-运动协同配置主要包括哪两方面的内容-说明其特点和应用。">38. 运动协同配置主要包括哪两方面的内容,说明其特点和应用。</h3><p>(1)多机械单元协调运动功能:可以支持多项运动任务、支持多种协同模式。</p><p>应用:多机器人独立运动;多机器人对同一个运动工件进行处理;一个机器人握持工具,一个机器人握持工件,协同处理。</p><p>(2)输送链跟踪功能:通过输送链跟踪板卡可以同时跟踪多个工件,同时支持圆弧跟踪。</p><p>应用:喷涂跟踪;拾料跟踪;线性跟踪;圆弧跟踪;步进跟踪。</p><h3 id="39-机器人结构设计时-机械强度校核的主要内容包括哪些-有哪些注意事项">39. 机器人结构设计时,机械强度校核的主要内容包括哪些,有哪些注意事项?</h3><p>(1)挠度变形计算</p><p>涉及的参数有负载、定位单元长度、材料弹性模量、材料截面惯性矩及挠度形变。</p><p>注意:1)计算静态形变的挠度形变时,梁的自重按均布载荷计算。</p><p>2)计算由于加速、减速产生的惯性力所产生的形变。</p><p>(2)扭转形变计算</p><p>当一根梁的一端固定,另一端施加一个绕轴扭矩后,将产生扭曲变形。</p><h3 id="40-说明机器人的三种运动模式及其特点。">40. 说明机器人的三种运动模式及其特点。</h3><p>机器人运动模式包括单轴运动模式、线性运动模式及重定位运动模式。</p><p>①单轴运动模式:单独控制某一个关节轴运动,机器人末端轨迹难以预测,一般只用于移动某个关节轴至指定位置、校准机器人关节原点等场合。</p><p>②线性运动模式:控制机器人TCP沿着指定的参考坐标系的坐标轴方向进行移动,在运动过程中工具的姿态不变,常用于空间范围内移动机器人TCP位置。</p><p>③重定位运动模式:某些特定情况下,需要重新定位工具的方向,使其与工件保持特定的角度,以便获得最佳效果。</p><h3 id="41-叙述机器人操作机结构设计的步骤。">41. 叙述机器人操作机结构设计的步骤。</h3><p>(1)明确与机器人相关联的工艺装备、检测设备等对操作机结构的影响因素。</p><p>(2)绘制机器人总体布置方案图,在图中明确机器人操作机的具体位置。</p><p>(3)分析机器人的特征参数、相关工艺参数及技术要求,设计机器人结构简图,进行机器人操作机的设计。</p><p>(4)机器人操作机设计初稿完成后,必须满足其基本功能需要。</p><p>(5)进行机器人操作机结构的详细设计、工艺设计等。</p><h3 id="42-试说明滚珠丝杠-螺母传动的特点。">42. 试说明滚珠丝杠-螺母传动的特点。</h3><p>(1)传动效率高;效率高达90%-95%,耗费的能量仅为滑动丝杠的1/3。</p><p>(2)运动具有可逆性;既可将回转运动变为直线运动,又可将直线运动变为回转运动,逆传动效率几乎与正传动效率相同。</p><p>(3)系统刚度好;通过给螺母组件内施加预压力来获得较高的系统刚度,可满足各种机械传动要求,无爬行现象,始终保持运动的平稳性和灵敏性。</p><p>(4)传动精度高;经过淬硬并精磨螺纹滚道后的滚珠丝杠副本身具有很高的制造精度,又由于摩擦小,丝杠副工作时温升小、热变形小,容易获得较高的传动精度。</p><p>(5)使用寿命长;滚珠是在淬硬的滚道上作滚动运动,磨损极小,长期使用后仍能保持其精度,因而寿命长,且具有很高的可靠性。其寿命一般比滑动丝杠高5-6倍。</p><p>(6)不能自锁;特别是垂直安装的滚珠丝杠,当运动停止后,螺母将在重力作用下下滑,故常需设置制动装置。</p><p>(7)工艺复杂;滚珠丝杠和螺母等零件加工精度、表面粗糙度要求高,制造成本高。</p><h3 id="43-工业机器人使用气缸驱动时-调速方法有哪几种选择">43. 工业机器人使用气缸驱动时,调速方法有哪几种选择?</h3><p>(1)用电磁换向阀的排气口节流调速。</p><p>(2)用快速排气阀的排气口节流调速。因其排气阀的阀口比较大,换向快,所以如果把它装置在最接近气缸处,则可加快启动速度。</p><p>(3)在进气路或排气路上装置单向节流阀调速。采用节流调速时,应尽可能用排气节流,而不用进气口节流。因为排气节流可使气缸产生背压,可提高工作的平稳性。</p><p>(4)采用气液联合传动实现调速。因为油缸一端可以加入单向阀或采用端部阻尼结构,借以调速。</p><h3 id="44-试说明机器人在工业生产中的作用。">44. 试说明机器人在工业生产中的作用。</h3><p>(1)提高生产过程的自动化程度;</p><p>(2)改善劳动条件、避免人身事故;</p><p>(3)减少人力,便于有节奏的生产。</p><h3 id="45-简述工业机器人中使用轴承的作用及特点。">45. 简述工业机器人中使用轴承的作用及特点。</h3><p>轴承是支承元件,主要功能是支承机械旋转体,用以降低设备在传动过程中的机械载荷摩擦系数。工业机器人的轴承是其关键配套件之一,最适用于工业机器人的关节部位或者旋转部位。</p><p>特点:</p><p>(1)可承受轴向、径向、倾覆等方向综合载荷;</p><p>(2)一般采用薄壁型轴承;</p><p>(3)具有较高的回转定位精度。</p><h3 id="46-试述工业机器人的手腕设计应满足的要求。">46. 试述工业机器人的手腕设计应满足的要求。</h3><p>（1）由于手腕处于手臂末端，为减轻手臂的载荷，应力求手腕部件的结构紧凑，减小其质量和体积。为此腕部机构的驱动装置多采用分离传动，将驱动器安置在手臂的后端。</p><p>（2）手腕部件的自由度愈多，各关节角的运动范围愈大，其动作的灵活性愈高，机器人对作业的适应能力也愈强。但增加手腕自由度，会使手腕结构复杂，运动控制难度加大。因此，设计时，不应盲目增加手腕的自由度数。通用目的机器手手腕多配置三个自由度，某些动作简单的专用工业机器人的手腕，根据作业实际需要，可减少其自由度数，甚至可以不设置手腕，以简化结构。</p><p>（3）为提高手腕动作的精确性。应提高传动的刚度，应尽量减少机械传动系统中由于间隙产生的反转回差。如齿轮传动中的齿侧间隙、丝杠螺母中的传动间隙、联轴器的扭转间隙等。对分离传动采用链、同步齿带传动或传动轴。</p><p>（4）对手腕回转各关节轴上要设置限位开关和机械挡块，以防止关节超限造成事故。</p><h3 id="47-工业机器人的手臂伸缩及升降运动机构上常设置导向装置，其目的有哪些？">47. 工业机器人的手臂伸缩及升降运动机构上常设置导向装置，其目的有哪些？</h3><p>答：（1）防止移动部件在伸缩及升降时产生不必要的转动，以保证手臂运动方位的准确性；</p><p>（2）增大移动部件的刚性，减少移动部件由于自重与抓取重量所引起的变形和位移；</p><p>（3）承受移动部件的部分自重和抓取工件(或工具)的部分重量。</p><h3 id="48-试说明电磁吸盘吸附式手部中电磁铁的工作原理？">48. 试说明电磁吸盘吸附式手部中电磁铁的工作原理？</h3><p>答：当缠绕在铁芯外部的线圈通电后，在铁心内外产生磁场，磁力线经过铁心，空气隙和衔铁被磁化并形成回路，衔铁受到电磁吸力的作用被牢牢吸住。盘式电磁铁中，衔铁是固定的，在衔铁内用隔磁材料将磁力线切断，当衔铁接触由铁磁材料制成的工件时，工件将被磁化，形成磁力线回路并受到电磁吸力而被吸住。一旦断电，电磁吸力即消失，工件因此被松开。</p><h3 id="49-试述分布式控制系统的原理及特点。">49. 试述分布式控制系统的原理及特点。</h3><p>分布式控制系统按系统的性质和方式分成几个模块,每一个模块各有不同的控制任务和控制策略,各模式之间可以是主从关系,也可以是平等关系。其主要思想是“分散控制,集中管理”,即系统对其总体目标和任务可以进行综合协调和分配,并通过子系统的协调工作来完成控制任务,整个系统在功能、逻辑和物理等方面都是分散的,所以又称为集散控制系统或分散控制系统。</p><p>这种方式实时性好,易于实现高速、高精度控制,易于扩展,可实现智能控制,是目前流行的方式。系统灵活性好,控制系统的危险性降低,采用多处理器的分散控制,有利于系统功能的并行执行,提高系统的处理效率,缩短响应时间。对于具有多自由度的工业机器人而言,当轴的数量增加到使控制算法变得很复杂时,其控制性能会恶化,甚至可能会导致系统的重新设计。</p><h3 id="50-机器人控制器的主要功能是什么？">50. 机器人控制器的主要功能是什么？</h3><p>（1）示教功能。主要包括在线示教和离线示教两种方式。</p><p>（2）记忆功能。存储作业顺序、运动路径和方式以及与生产工艺有关的信息等。</p><p>（3）位置伺服功能。机器人多轴联动、运动控制、速度和加速度控制、动态补偿等。</p><p>（4）坐标设定功能。可在关节、直角、工具等常见坐标系之间进行切换。</p><p>（5）与外围设备联系功能。包括输入/输出投接口、通信接口、网络接口等。</p><p>（6）传感器接口。位置检测、视觉、触觉、力觉等。</p><p>（7）故障诊断安全保护功能。运行时的状态监视、故障状态下的安全保护和自诊断。</p><h3 id="51-试述机器人的驱动类型及各自的特点">51. 试述机器人的驱动类型及各自的特点?</h3><p>(1)气压驱动:优点空气来源方便,动作迅速,结构简单,造价低;缺点是空气具有可压缩性,工作速度的稳定性较差,因气源的压力较低,所以此类机器人适宜在对抓举力要求小的场合。</p><p>(2)液压驱动:相对于气压驱动,液压驱动的机器人具有大得多的抓举力,抓举质量可高达上百千克。液压驱动机器人结构紧凑,传动平稳且动作灵敏,但对密封的要求较高,且不宜在高温或低温的场合工作,要求的制造精度较高,成本较高。</p><p>(3)电力驱动:具有无污染、易于控制、运动精度高、成本低、驱动效率高等优点,其应用最广泛。</p><h3 id="52-试述集中式控制系统的原理及其优缺点。">52. 试述集中式控制系统的原理及其优缺点。</h3><p>由一台计算机实现全部控制功能。基于PC的集中控制系统里,充分利用PC资源开放性的特点,可以实现很好的开放性。多种控制卡,传感器设备等都可通过标准PCI插槽或通过标准串口、并口集成到控制系统中。</p><p>优点:结构简单,硬件成本较低,便于信息的采集和分析,易于实现系统的最优控制,整体性与协调性较好,基于PC的系统硬件扩展较为方便。</p><p>缺点:灵活性、实时性、可靠性较差。</p><h3 id="53-简述交叉滚子轴承的特点。">53. 简述交叉滚子轴承的特点。</h3><p>(1)具有出色的旋转精度</p><p>内外环是分割的结构,间隙可调整,即使被施加预压,也能获得高精度的旋转运动。</p><p>(2)操作安装简化</p><p>分割的内外环,在装入滚子和保持器后,被固定在一起,所以安装时操作非常简单。</p><p>(3)承受较大的轴向和径向负荷</p><p>滚子在呈90°的V型沟槽滚动面上通过间隔保持器被相互垂直排列,可承受较大的负荷。</p><p>(4)大幅节省安装空间</p><p>内外环尺寸被最小限度的小型化,特别是超薄结构接近极限的小型尺寸,并具有高刚性。</p><h3 id="54-按照工业机器人服务的生产形式可将其分为哪几种类型">54. 按照工业机器人服务的生产形式可将其分为哪几种类型?</h3><p>铸造生产中的工业机器人、锻压设备中的工业机器人、金属切削机床用的工业机器人、装配用工业机器人、金属电镀车间设备用工业机器人等。</p><h3 id="55-根据其自由的构成方法，关节型机器人可分为哪几种类型，试说明其特点？">55. 根据其自由的构成方法，关节型机器人可分为哪几种类型，试说明其特点？</h3><p>（1）仿人关节型机器人，在标准手臂上再加一个自由度(冗余自由度)。</p><p>（2）平行四边形连杆关节型机器人。手臂采用平行四边形连杆，并把前臂关节驱动用的电动机安装在手臂的根部，可获得更高的运动速度。</p><p>（3）SCARA型机器人。手臂前端采用能够在二维空间自由移动的自由度，因此其在垂直方向具有刚性高，水平面内柔顺性好的特点。</p><h3 id="56-试述气吸式末端执行器的类型及各自特点。">56. 试述气吸式末端执行器的类型及各自特点。</h3><p>答：气吸式末端执行器有挤压排气式吸盘、气流负压式吸盘和真空泵排气式吸盘三种。</p><p>(1) 挤压排气式吸盘靠向下挤压力将吸盘内的空气排出，使其内部形成负压，将工件吸住。结构简单、质量小，成本低的优点，但吸力不大，多用于吸取尺寸不大，薄而轻物体。</p><p>(2)气流负压式吸盘控制阀将来自气泵的压缩空气自喷嘴通人，形成高速射流，将吸盘内腔中的空气带走而形成负压，使吸盘吸住物体。这种吸盘比较方便，且成本低。</p><p>(3)真空泵排气式吸盘利用电磁控制阀将吸盘与真空泵相联，当抽气时，吸盘腔内的空气被抽出，形成负压而吸住物体。这种吸盘工件可靠，吸力大，但需配备真空泵及其控制系统，费用较高。</p><h3 id="57-机器人的机械结构配置可以由哪些特征来决定">57. 机器人的机械结构配置可以由哪些特征来决定?</h3><p>(1)机动性;</p><p>(2)支承系统的形式和结构;</p><p>(3)手臂数目;</p><p>(4)夹持器。</p><h3 id="58-什么是工业机器人的末端执行器，机器人末端执行器的特点有哪些？">58. 什么是工业机器人的末端执行器，机器人末端执行器的特点有哪些？</h3><p>末端执行器也叫手部，是直接装在工业机器人的手腕上用于夹持工件或让工具按照规定的程序完成指定的工作。</p><p>（1）和腕部相连处可拆卸 ；</p><p>（2）形态各异；</p><p>（3）通用性较差；</p><p>（4）是一个独立的部件；</p><h3 id="59-简述常用的机器人运动控制器有哪几种类型">59. 简述常用的机器人运动控制器有哪几种类型?</h3><p>(1)以单片机为核心的机器人控制系统;</p><p>(2)以可编程控制器(PLC)为核心的机器人控制系统;</p><p>(3)基于工业个人计算机(IPC)+运动控制器的机器人控制系统。</p><h3 id="60-滚珠丝杠副常用的消除轴向间隙的方法哪些">60. 滚珠丝杠副常用的消除轴向间隙的方法哪些?</h3><p>(1)双螺母螺纹预紧调隙式</p><p>(2)双螺母齿差预紧调隙式</p><p>(3)双螺母垫片预紧调隙式</p><p>(4)弹簧式自动调整预紧式</p><h3 id="61-试述工业机器人手臂机构设计的要求。">61. 试述工业机器人手臂机构设计的要求。</h3><p>答：</p><p>1.手臂应具有足够的承受能力和刚度</p><pre><code>    为防止工业机器人的臂部在运动过程中产生过大的变形，手臂的截面形状要合理选择。工字形截面构件的弯曲刚度一般比圆截面构件的要大；空心轴的弯曲刚度和扭转刚度都比心轴大得多，所以常用钢管做臂杆及导向杆，用工字钢和槽钢做支承板。</code></pre><ol start="2"><li><p>导向性要好</p><pre><code> 为防止工业机器人的臂部在直线运动过程中，沿运动轴线发生相对转动，应设置导向装置或设计方形、花键等形式的臂杆。导向装置的具体结构形式一般应根据载荷大小、手臂长度、行程以及手臂的安装形式等因素来决定。导轨的长度不宜小于其间距的2倍，以保证导向性良好。</code></pre></li><li><p>重量要轻、转动惯量要小</p><pre><code> 为提高工业机器人的运动速度，要尽量减小臂部运动部分的重量，以减小整个手臂对回转轴的转动惯量。此外，为防止工业机器人臂部在升降过程中发生卡死或爬行现象，还意减小偏重力矩，尽量减小臂部运动部分的重量，使臂部的重心与立柱中心尽量靠近，此外还可以采取“配重”的方法来减小和消除偏重力矩。</code></pre></li><li><p>运动要平稳、定位精度要高</p><pre><code> 由于工业机器人的臂部运动速度越高，惯性力引起的定位前的冲击也就越大，导致运动既不平稳，定位精度又不高。因此，除了臂部设计上要力求结构紧凑、重量轻外，还要采用一定形式的缓冲措施。工业机器人常用的缓冲装置有弹性缓冲元件、液压(气)缸端部缓冲装置、缓冲回路和液压缓冲器等。按照在机器人或机械手结构中设置位置的不同，可分为内部缓冲装置和外部缓冲装置两类。</code></pre></li></ol><p>5.合理设计与腕和机身的连接部位</p><pre><code>    因为工业机器人臂部的安装形式和位置不仅关系到工业机器人的强度、刚度和承载能力，还直接影响工业机器人的外观，在结构设计中应全面地考虑所采用的各元器件与机构的特点和特性、作业和控制要求，进行合理布局，处理具体结构。</code></pre><h3 id="62-什么是手臂的偏重力矩，偏重力矩何时达到最大？偏重力矩对手臂升降运动的灵活性有何影响？">62. 什么是手臂的偏重力矩，偏重力矩何时达到最大？偏重力矩对手臂升降运动的灵活性有何影响？</h3><p>（1）偏重力矩是指臂部全部零部件与抓取的总重量对手臂回转轴的静力矩。</p><p>（2）手臂悬伸最长行程时,其偏重力矩为最大,故偏重力矩应按悬伸最大行程、最大抓重时进行计算。</p><p>（3）如果偏重力矩过大，可能会使手臂立柱被卡死在导套内而不能作升降运动</p><h3 id="63-柔顺装配包含几种类型？各有何特点？">63. 柔顺装配包含几种类型？各有何特点？</h3><p>（1）主动柔顺装配</p><p>从检测、控制的角度，采取各种不同的搜索方法，实现边校正边装配。</p><p>特点：需装配一定功能的传感器，价格较贵；另外，由于反馈控制响应能力的限制，装配速度较慢。</p><p>（2）被动柔顺装配</p><p>从机械结构的角度在手腕部配置一个柔顺环节，以满足柔顺装配的需要。</p><p>特点：结构比较简单，价格比较便宜，装配速度较快。</p><h3 id="64-试述主从控制系统的原理及特点。">64. 试述主从控制系统的原理及特点。</h3><p>采用主、从两级处理器实现系统的全部控制功能。主CPU实现管理、坐标变换、轨迹生成和系统自诊断等;从CPU实现所有关节的动作控制。主从控制方式系统实时性较好,适于高精度、高速度控制,但其系统扩展性较差,维修困难。</p><h3 id="65-试述工业机器人机座结构设计的要求。">65. 试述工业机器人机座结构设计的要求。</h3><p>（1）要有足够大的安装基面，以保证机器人工作时的稳定性。</p><p>（2）机座承受机器人全部重力和工作载荷，应保证足够的强度、刚度和承载能力。</p><p>（3）机座轴系及传动链的精度和刚度对末端执行器的运动精度影响最大。因此机座与手臂的联接要有可靠的定位基准面，要有调整轴承间隙和传动间隙的调整机构。</p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;填空题&lt;/h1&gt;
&lt;h2 id=&quot;机器人系统组成与基本特征&quot;&gt;机器人系统组成与基本特征&lt;/h2&gt;
&lt;ol&gt;
&lt;li&gt;工业机器人系统一般包括&lt;strong&gt;机械系统、驱动系统、控制系统&lt;/strong&gt;三个基本组成部分。&lt;/li&gt;
&lt;li&gt;机器人本体也称&lt;strong&gt;操作</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>使用公网ipv6远程连接sunshine</title>
    <link href="http://example.com/post/ae738c2f.html"/>
    <id>http://example.com/post/ae738c2f.html</id>
    <published>2025-05-24T10:12:33.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>准备</h1><p>本文中所使用的设备：</p><ul><li>拥有公网ipv6的宽带一条</li><li>域名一个，用于配置DDNS</li><li>Openwrt路由器一台</li><li>Windows电脑一台，装有sunshine</li></ul><h1>配置windows ipv6</h1><p>Windows系统的IPv6默认使用随机生成的IPv6地址，并添加一个或多个临时地址，存在临时地址的时候访问网络优先使用临时地址，当遇到服务端需要设置IP白名单并且用户IPv6前缀无法保持不变的时候就不能使用这种临时地址与随机地址了，这时候要把系统的IPv6配置为基于EUI-64生成的固定后缀地址来方便服务端配置防火墙。<br>首先使用管理员权限打开PowerShell，输入<code>Get-NetIPv6Protocol</code>回车可以看到当前的IPv6设置.</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br></pre></td><td class="code"><pre><span class="line">(base) PS C:\Users\28071&gt; Get-NetIPv6Protocol</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">DefaultHopLimit               : 128</span><br><span class="line">NeighborCacheLimit(Entries)   : 256</span><br><span class="line">RouteCacheLimit(Entries)      : 4096</span><br><span class="line">ReassemblyLimit(Bytes)        : 128811488</span><br><span class="line">IcmpRedirects                 : Enabled</span><br><span class="line">SourceRoutingBehavior         : DontForward</span><br><span class="line">DhcpMediaSense                : Enabled</span><br><span class="line">MediaSenseEventLog            : Disabled</span><br><span class="line">MldLevel                      : All</span><br><span class="line">MldVersion                    : Version2</span><br><span class="line">MulticastForwarding           : Disabled</span><br><span class="line">GroupForwardedFragments       : Disabled</span><br><span class="line">RandomizeIdentifiers          : Enabled</span><br><span class="line">AddressMaskReply              : Disabled</span><br><span class="line">UseTemporaryAddresses         : Enabled</span><br><span class="line">MaxTemporaryDadAttempts       : 3</span><br><span class="line">MaxTemporaryValidLifetime     : 7.00:00:00</span><br><span class="line">MaxTemporaryPreferredLifetime : 7.00:00:00</span><br><span class="line">TemporaryRegenerateTime       : 00:00:05</span><br><span class="line">MaxTemporaryDesyncTime        : 00:10:00</span><br><span class="line">DeadGatewayDetection          : Enabled</span><br><span class="line"></span><br></pre></td></tr></table></figure><p>可以看到RandomizeIdentifiers与UseTemporaryAddresses默认为启用状态，也就是生成随机地址与使用临时地址，需要禁用掉这两个选项才能使用基于EUI-64的IPv6地址。</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">(base) PS C:\Users\28071&gt; Set-NetIPv6Protocol -UseTemporaryAddresses Disabled</span><br><span class="line">(base) PS C:\Users\28071&gt; Set-NetIPv6Protocol -RandomizeIdentifiers Disabled</span><br></pre></td></tr></table></figure><p>执行完上面两条命令后可以再次执行Get-NetIPv6Protocol看看修改是否生效，生效后断开网络连接重连即可看到系统当前就只有基于EUI-64生成的IPv6地址了。<br>然后我们需要获取到自己电脑的ipv6公网地址，一般是以240开头，我们需要的是后半部分，例如<code>280:4dff:fe38:1673</code>,这一段是由电脑的mac地址决定的，如果上面正常的话，最中间的四位应该为<code>ff:fe</code>。保存下这串字符后面要用。</p><h1>设置DDNS-GO</h1><h2 id="配置DNS提供商的token">配置DNS提供商的token</h2><p>根据你所拥有的域名提供商不同，所需的配置方式也略有不同。以cloudflare为例，依次点击右上角账户——配置文件——API令牌——创建令牌——使用 编辑区域 模板——在 区域资源处设置“包括 特定区域 你的域名” 。设置完成后点击继续以显示摘要——创建令牌。此时屏幕会出现一串字符，点击copy复制保存下来，这样我们的token就获取到了。注意要保存好token，此页面关闭后将无法再次查看。</p><h2 id="OpenWrt配置ddns-go">OpenWrt配置ddns-go</h2><p>在openwrt的软件包安装界面先点击更新列表，然后搜索<code>luci-app-ddns-go</code>,点击安装，完成后刷新页面。<br>现在在服务里找到DDNS-GO,勾选启用后保存并应用。在应用完成后会出现 <code>打开Web页面</code>，点击后跳转到ddns-go的配置页面。<br>首先配置用户名和密码，完成后会进入主界面。在DNS服务商出勾选对应的服务商，将上一步获取的token粘贴到Token出。<br>找到IPv6部分，勾选启用，获取获取 IP 方式设置为通过命令获取，在下面填入</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">ip -6 route | awk &#x27;&#123;print $1&#125;&#x27; | awk &#x27;/240:?/&#x27; | awk -F::/ &#x27;&#123;print $1 &quot;:suffix of other mac&quot;&#125;&#x27;</span><br></pre></td></tr></table></figure><p>其中将suffix of other mac替换为上面获取到的你的ipv6地址的后半部分。在Domains内填入你想配置的子域名。最后点击保存，这样就配置好了。查看日志可以看到配置成功。</p><h1>配置openwrt防火墙</h1><p>找到openwrt的网络-防火墙-通信规则，点击添加。源区域设为<code>wan</code>目标地址为</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">::suffix of other mac/::ffff:ffff:ffff:ffff</span><br><span class="line"></span><br></pre></td></tr></table></figure><p>其中suffix of other mac 还是替换成你的地址,目标端口设置为<code>47980-48020</code>,操作改为<code>接受</code>.保存并应用,这样防火墙就配置好了</p><p>最后不要忘记在sunshine控制台-network-Address Family设置ipv4+ipv6.</p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;准备&lt;/h1&gt;
&lt;p&gt;本文中所使用的设备：&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;拥有公网ipv6的宽带一条&lt;/li&gt;
&lt;li&gt;域名一个，用于配置DDNS&lt;/li&gt;
&lt;li&gt;Openwrt路由器一台&lt;/li&gt;
&lt;li&gt;Windows电脑一台，装有sunshine&lt;/li&gt;
&lt;/ul&gt;</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>机器人原理</title>
    <link href="http://example.com/post/b3a96a80.html"/>
    <id>http://example.com/post/b3a96a80.html</id>
    <published>2025-05-12T12:11:10.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>填空题</h1><h2 id="机器人结构">机器人结构</h2><ol><li>机器人机械结构的基本元素为连杆和关节。其中，机器人的关节只选用低副，其中最常用的低副是<strong>旋转副和移动副</strong>。</li><li>在机器人学中，可以在机器人的每个连杆（关节）、手腕、末端执行器以及工件上建立多个坐标系。这些坐标系由于与运动部件相连接，称之为<strong>相对坐标系</strong>；与此对应的基坐标系则称之为<strong>绝对坐标系</strong>。</li><li>机器人操作臂通常是由一系列连杆和相应的运动副组合而成的<strong>空间开链结构</strong>,用于实现复杂的运动，完成规定的操作。</li><li>在机器人运动过程中，为了描述机器人连杆、关节、末端执行器工件等实体位置，建立相对坐标系与绝对坐标系之间的一一映射关系则称之为<strong>坐标变换</strong>。</li><li>在手爪坐标系{T}中，其z轴设在手爪<strong>接近</strong>物体的方向，z轴单位矢量成为<strong>接近矢量</strong>，用a表示；y轴设在两手指的连线方向，y轴单位矢量称为<strong>方位矢量</strong>，用o表示；x轴方向由<strong>右手法则</strong>确定，其单位矢量称为法向矢量，用n表示。</li><li>若坐标系{B}在坐标系{A}下的旋转矩阵为<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mrow></mrow><mi>B</mi><mi>A</mi></msubsup><mi>R</mi></mrow><annotation encoding="application/x-tex">_B^AR</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.1167em;vertical-align:-0.2753em;"></span><span class="mord"><span></span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8413em;"><span style="top:-2.4247em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.05017em;">B</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">A</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2753em;"><span></span></span></span></span></span></span><span class="mord mathnormal" style="margin-right:0.00773em;">R</span></span></span></span>，刚体的旋转在坐标系{B}下的角速度为<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>ω</mi><mi>B</mi></msub></mrow><annotation encoding="application/x-tex">\omega_B</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.5806em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">ω</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3283em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span>，根据角速度的定义，刚体在坐标系{A}下的角速度为<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>ω</mi><mi>A</mi></msub><msubsup><mo>=</mo><mi>B</mi><mi>A</mi></msubsup><mi>R</mi><msub><mi>ω</mi><mi>B</mi></msub></mrow><annotation encoding="application/x-tex">\omega_A=_B^AR \omega_B</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.1167em;vertical-align:-0.2753em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">ω</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3283em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">A</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel"><span class="mrel">=</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8413em;"><span style="top:-2.4247em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.05017em;">B</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">A</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2753em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord mathnormal" style="margin-right:0.00773em;">R</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">ω</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3283em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span> 。</li><li>运动学方程的封闭解可通过两种途径获得:<strong>代数方法和几何方法</strong> 。</li><li>在机器人末端法兰盘上的工具中心点建立的笛卡尔坐标系称为<strong>工具坐标系</strong>。</li><li>当构件坐标系{B}与参考坐标系{A}的姿态相同时，只需表示位置关系时，有<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mrow></mrow><mi>A</mi><mi>B</mi></msubsup><mi>R</mi><mo>=</mo><mi>I</mi></mrow><annotation encoding="application/x-tex">_A^BR=I</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.1167em;vertical-align:-0.2753em;"></span><span class="mord"><span></span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8413em;"><span style="top:-2.4247em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">A</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2753em;"><span></span></span></span></span></span></span><span class="mord mathnormal" style="margin-right:0.00773em;">R</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07847em;">I</span></span></span></span>；当构件坐标系{B}与参考坐标系{A}的原点相同时，只需表示姿态关系时，有<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow></mrow><mi>A</mi></msub><msub><mi>P</mi><mrow><mi>B</mi><mi>O</mi></mrow></msub><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">_AP_{BO}=0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord"><span></span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3283em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">A</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3283em;"><span style="top:-2.55em;margin-left:-0.1389em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.02778em;">BO</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>。</li><li>大地坐标系也称为世界坐标系，常用于多台机器人的<strong>协调控制</strong>。</li><li>典型工业机器人的机械本体多采用关节式机械结构，一般具有6个自由度，其中3个用来确定末端执行器的<strong>位置</strong>，另外3个则用来确定末端执行装置的**方向（姿态）。</li><li>当旋转运动R是相对于固定坐标系进行时，用R<strong>左乘</strong>乘相应的矩阵。</li><li>机器人系统包括机器人机械系统、<strong>驱动系统</strong> 、<strong>控制系统</strong>  和感知系统等四部分。</li><li>在机器人学中，一个位姿可以等价地用一个<strong>位置矢量</strong>和一个<strong>旋转矩阵</strong>来描述。</li><li>两连杆之间通过面接触相对运动时，接触面的压强低，这样的运动副称为<strong>低副</strong> ；连杆之间通过线接触或点接触相对运动时，接触面的压强高，则称为<strong>高副</strong> 。</li><li>在机器人运动过程中，为了描述机器人连杆、关节、末端执行器、工件等实体位置，建立相对坐标系与绝对坐标系之间的一一映射关系则称之为 <strong>坐标变换</strong> 。</li><li>机器人的感知能力由传感系统实现，可用于检测和收集内外环境状况信息，包括<strong>内部传感器</strong>和<strong>外部传感器</strong> 两大类。</li><li>由机器人关节空间到机器人工作空间的映射称为<strong>正运动学</strong>，由机器人工作空间到机器人关节空间的映射称为<strong>逆运动学</strong>。</li></ol><h2 id="正运动学">正运动学</h2><ol><li>在进行正运动学分析时，常常用到<strong>DH参数法</strong>进行坐标变换，以便描述机器人各关节的位置。在使用DH（Denavit-Hartenberg）参数法时，常常会设置<strong>局部坐标系</strong>坐标系，来描述每个关节的相对位置。</li><li>正运动学的核心任务是通过已知的<strong>关节角度</strong>和<strong>关节长度</strong>来求解末端执行器的位姿。</li><li>机械臂的正运动学求解通常依赖于<strong>齐次</strong>变换，它可以通过旋转矩阵和位移向量来描述。</li><li>1955年，Denavit和Hartenberg提出了一种基于<strong>齐次变换矩阵</strong>的低副机构建模方法，该建模方法被称为D-H法。</li></ol><h2 id="逆运动学">逆运动学</h2><ol><li>机器人运动学问题中，逆运动学的计算方法有时需要通过<strong>数值</strong>算法求解。</li><li>对于逆运动学，通常情况下需要考虑关节的<strong>可达</strong>性问题，即某些关节角度会导致不可达的情况。</li><li>在求机械臂运动学逆问题时可能出现多解现象，即同一位姿对应于多于一组的关节变量，称为退化问题。求逆时，也可能存在奇异问题，当进行逆变换的计算时要做除法，而当分母趋于<strong>零</strong>时便会出现奇异现象。</li><li>机器人逆运动学解的存在性问题取决于机器人的<strong>工作空间</strong>。</li></ol><h1>主观题与简答题</h1><h3 id="1-简述齐次变换矩阵的作用，并列出其基本形式。">1. 简述齐次变换矩阵的作用，并列出其基本形式。</h3><p>齐次变换矩阵用于描述机器人关节之间的空间变换（位置与姿态变换），并且能够简化多个变换的组合运算。它是一个4x4的矩阵，包含了旋转矩阵和位移向量。</p><p>基本形式为：</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>T</mi><mo>=</mo><mrow><mo fence="true">(</mo><mtable rowspacing="0.16em" columnalign="center center" columnspacing="1em"><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mi>R</mi></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mi>d</mi></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>0</mn></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mn>1</mn></mstyle></mtd></mtr></mtable><mo fence="true">)</mo></mrow></mrow><annotation encoding="application/x-tex"> T = \begin{pmatrix}R&amp;d\\0&amp;1\end{pmatrix}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">T</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.4em;vertical-align:-0.95em;"></span><span class="minner"><span class="mopen delimcenter" style="top:0em;"><span class="delimsizing size3">(</span></span><span class="mord"><span class="mtable"><span class="col-align-c"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.45em;"><span style="top:-3.61em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.00773em;">R</span></span></span><span style="top:-2.41em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.95em;"><span></span></span></span></span></span><span class="arraycolsep" style="width:0.5em;"></span><span class="arraycolsep" style="width:0.5em;"></span><span class="col-align-c"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.45em;"><span style="top:-3.61em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span></span></span><span style="top:-2.41em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.95em;"><span></span></span></span></span></span></span></span><span class="mclose delimcenter" style="top:0em;"><span class="delimsizing size3">)</span></span></span></span></span></span></span></p><p>其中，R是3x3旋转矩阵，d是3x1位移向量，0是一个1x3零向量。</p><h3 id="2-什么叫冗余自由度机器人？">2. 什么叫冗余自由度机器人？</h3><p>[AI]冗余自由度机器人是指自由度数量超出任务需求，用于提升灵活性、避障及运动优化的机器人。</p><h3 id="3-简述确定手爪坐标系的方法。">3. 简述确定手爪坐标系的方法。</h3><ul><li>见P96页。</li></ul><p>在手爪坐标系{T}中，其z轴设在手爪<strong>接近</strong>物体的方向，z轴单位矢量成为<strong>接近矢量</strong>，用a表示；y轴设在两手指的连线方向，y轴单位矢量称为<strong>方位矢量</strong>，用o表示；x轴方向由<strong>右手法则</strong>确定，其单位矢量称为法向矢量，用n表示。</p><h3 id="4-简述如何使用牛顿-欧拉方法求解机器人的动力学方程。">4. 简述如何使用牛顿-欧拉方法求解机器人的动力学方程。</h3><p>牛顿-欧拉方法通过分别对机器人各个连杆的线性和角动量方程进行求解，结合力和力矩平衡方程，得出每个关节的力矩和加速度。具体步骤包括：</p><p>计算每个连杆的线速度和角速度；</p><p>根据线速度和角速度计算出连杆的惯性力矩；</p><p>使用力矩平衡方程计算每个关节的力矩。</p><h2 id="5-简述机器人的定义。">5. 简述机器人的定义。</h2><p>[AI]机器人是通过编程人工智能技术控制，具备感知、决策与执行能力，完成任务的自动化机器装置。</p><h3 id="6-简述如何使用Denavit-Hartenberg-DH-参数来描述机械臂的运动学。">6. 简述如何使用Denavit-Hartenberg(DH)参数来描述机械臂的运动学。</h3><p>DH参数：用来描述机器人每个关节的变换关系，共包括四个参数：关节角（θ）、连杆长度（d）、连杆偏移（a）和扭转角（α）。这些参数通过旋转和位移矩阵定义了一个连杆到下一个连杆的变换关系。</p><p>应用：通过连续应用DH变换矩阵，可以得到整个机械臂的正向运动学模型。每个变换矩阵都依赖于一个关节的DH参数，最终得到末端执行器相对于基坐标系的位置和姿态。</p><h3 id="7-什么是机器人运动学逆解的多重性？">7. 什么是机器人运动学逆解的多重性？</h3><p>[AI]机器人运动学逆解的多重性是指给定末端执行器的位置和姿态时，存在多个不同的关节角度组合（逆解）满足该位姿要求的现象。</p><h3 id="8-简述阿西莫夫提出的的“机器人三原则”。">8. 简述阿西莫夫提出的的“机器人三原则”。</h3><p>第一条：机器人不得伤害人类，或看到人类受到伤害而袖手旁观。</p><p>第二条：机器人必须服从人类的命令，除非这条命令与第一条相矛盾。</p><p>第三条：机器人必须保护自己，除非这种保护与以上两条相矛盾。</p><h3 id="9-简述Pieper准则的内容？">9. 简述Pieper准则的内容？</h3><p>（1）三个相邻关节轴交于一点；</p><p>（2）三个相邻关节轴互相平行。</p><h3 id="10-简述正向运动学与逆向运动学的区别。">10. 简述正向运动学与逆向运动学的区别。</h3><p>正向运动学：根据给定的关节角度，利用运动学方程计算机器人末端执行器的位置和姿态。常通过已知的变换矩阵进行计算。</p><p>逆向运动学：给定末端执行器的位置和姿态，计算出机器人各关节的角度或位置。逆运动学通常存在多个解或者没有解，且求解较为复杂。</p><h3 id="11-简述机器人有几种坐标系？">11. 简述机器人有几种坐标系？</h3><ul><li>P46-47</li></ul><p>大地坐标系、基坐标系、关节坐标系、工具坐标系、工件坐标系和用户坐标系。</p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;填空题&lt;/h1&gt;
&lt;h2 id=&quot;机器人结构&quot;&gt;机器人结构&lt;/h2&gt;
&lt;ol&gt;
&lt;li&gt;机器人机械结构的基本元素为连杆和关节。其中，机器人的关节只选用低副，其中最常用的低副是&lt;strong&gt;旋转副和移动副&lt;/strong&gt;。&lt;/li&gt;
&lt;li&gt;在机器人学中，可以在机器人的</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>常微分方程</title>
    <link href="http://example.com/post/31dab94e.html"/>
    <id>http://example.com/post/31dab94e.html</id>
    <published>2025-04-01T13:02:34.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>一、常微分方程的概念</h1><h2 id="1-微分方程">1. 微分方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>=</mo><mi>y</mi><mo>+</mo><mi>x</mi><mspace width="1em"/><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>+</mo><msup><mi>y</mi><mn>3</mn></msup><mo>=</mo><mi>x</mi><mspace width="1em"/><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>=</mo><msup><mi>e</mi><mi>x</mi></msup></mrow><annotation encoding="application/x-tex">y&#x27; = y + x \quad y&#x27;&#x27; + y^3 = x \quad y&#x27;&#x27; = e^x </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7778em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:1em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.0585em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">3</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:1em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7144em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span></span></span></span></p><h2 id="2-微分方程的阶">2. 微分方程的阶</h2><h2 id="3-微分方程的解">3. 微分方程的解</h2><h2 id="4-微分方程的通解">4. 微分方程的通解</h2><p>含有独立常数的解称为通解，通解中含有的独立常数的个数与微分方程的阶数相同。</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>=</mo><msup><mi>e</mi><mi>x</mi></msup></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; = e^x </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7144em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>y</mi><mo>=</mo><msup><mi>e</mi><mi>x</mi></msup><mo>+</mo><msub><mi>C</mi><mn>1</mn></msub><mi>x</mi><mo>+</mo><msub><mi>C</mi><mn>2</mn></msub></mrow><annotation encoding="application/x-tex">y = e^x + C_1x + C_2 </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7977em;vertical-align:-0.0833em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0715em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0715em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span></span></p><h2 id="5-微分方程的特解">5. 微分方程的特解</h2><p>不含独立常数的解称为特解。</p><h2 id="6-微分方程的初始条件">6. 微分方程的初始条件</h2><p>初始条件是确定通解中独立常数的值的条件。</p><h2 id="7-微分方程的积分曲线">7. 微分方程的积分曲线</h2><h1>二、一阶微分方程</h1><p><strong>一般形式：</strong></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo separator="true">,</mo><mi>y</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27; = f(x, y) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span></span></span></span></span></p><h2 id="1-可分离变量的微分方程">1. 可分离变量的微分方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>g</mi><mo stretchy="false">(</mo><mi>y</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27; = f(x)g(y) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mrow><mi>d</mi><mi>y</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>g</mi><mo stretchy="false">(</mo><mi>y</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\frac{dy}{dx} = f(x)g(y) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.0574em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mrow><mi>d</mi><mi>y</mi></mrow><mrow><mi>g</mi><mo stretchy="false">(</mo><mi>y</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\frac{dy}{g(y)} = f(x)dx </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.3074em;vertical-align:-0.936em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.936em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo>∫</mo><mfrac><mrow><mi>d</mi><mi>y</mi></mrow><mrow><mi>g</mi><mo stretchy="false">(</mo><mi>y</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><mo>∫</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>+</mo><mi>C</mi></mrow><annotation encoding="application/x-tex">\int \frac{dy}{g(y)} = \int f(x)dx + C </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.3074em;vertical-align:-0.936em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.936em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.2222em;vertical-align:-0.8622em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07153em;">C</span></span></span></span></span></p><h2 id="2-齐次微分方程">2. 齐次微分方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>=</mo><mi>φ</mi><mo stretchy="false">(</mo><mfrac><mi>y</mi><mi>x</mi></mfrac><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27; = \varphi(\frac{y}{x}) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.7936em;vertical-align:-0.686em;"></span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.1076em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mclose">)</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mrow><mi>d</mi><mi>y</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>=</mo><mi>φ</mi><mo stretchy="false">(</mo><mfrac><mi>y</mi><mi>x</mi></mfrac><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\frac{dy}{dx} = \varphi(\frac{y}{x}) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.0574em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.7936em;vertical-align:-0.686em;"></span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.1076em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mclose">)</span></span></span></span></span></p><p>令 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>u</mi><mo>=</mo><mfrac><mi>y</mi><mi>x</mi></mfrac></mrow><annotation encoding="application/x-tex">u = \frac{y}{x}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">u</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0925em;vertical-align:-0.345em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.7475em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.4461em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">y</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span>，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>y</mi><mo>=</mo><mi>u</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">y = ux</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">ux</span></span></span></span>，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mfrac><mrow><mi>d</mi><mi>y</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>=</mo><mi>u</mi><mo>+</mo><mi>x</mi><mfrac><mrow><mi>d</mi><mi>u</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac></mrow><annotation encoding="application/x-tex">\frac{dy}{dx} = u + x\frac{du}{dx}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.2772em;vertical-align:-0.345em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9322em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.4461em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight" style="margin-right:0.03588em;">y</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">u</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.2251em;vertical-align:-0.345em;"></span><span class="mord mathnormal">x</span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8801em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">u</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>u</mi><mo>+</mo><mi>x</mi><mfrac><mrow><mi>d</mi><mi>u</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>=</mo><mi>φ</mi><mo stretchy="false">(</mo><mi>u</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">u + x\frac{du}{dx} = \varphi(u) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">u</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0574em;vertical-align:-0.686em;"></span><span class="mord mathnormal">x</span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">u</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">u</span><span class="mclose">)</span></span></span></span></span></p><p>化为可分离变量的微分方程：</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>x</mi><mfrac><mrow><mi>d</mi><mi>u</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>u</mi><mo stretchy="false">)</mo><mo>−</mo><mi>u</mi></mrow><annotation encoding="application/x-tex">x\frac{du}{dx} = f(u) - u </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.0574em;vertical-align:-0.686em;"></span><span class="mord mathnormal">x</span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">u</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">u</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">u</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mrow><mi>d</mi><mi>u</mi></mrow><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>u</mi><mo stretchy="false">)</mo><mo>−</mo><mi>u</mi></mrow></mfrac><mo>=</mo><mfrac><mrow><mi>d</mi><mi>x</mi></mrow><mi>x</mi></mfrac></mrow><annotation encoding="application/x-tex">\frac{du}{f(u) - u} = \frac{dx}{x} </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.3074em;vertical-align:-0.936em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">u</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal">u</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">u</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.936em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0574em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo>∫</mo><mfrac><mrow><mi>d</mi><mi>u</mi></mrow><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>u</mi><mo stretchy="false">)</mo><mo>−</mo><mi>u</mi></mrow></mfrac><mo>=</mo><mo>∫</mo><mfrac><mrow><mi>d</mi><mi>x</mi></mrow><mi>x</mi></mfrac><mo>+</mo><mi>C</mi></mrow><annotation encoding="application/x-tex">\int \frac{du}{f(u) - u} = \int \frac{dx}{x} + C </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.3074em;vertical-align:-0.936em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">u</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal">u</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">u</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.936em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.2337em;vertical-align:-0.8622em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07153em;">C</span></span></span></span></span></p><h2 id="3-一阶线性微分方程">3. 一阶线性微分方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>y</mi><mo>=</mo><mi>Q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27; + P(x)y = Q(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">Q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mrow><mi>d</mi><mi>y</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>+</mo><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>y</mi><mo>=</mo><mi>Q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\frac{dy}{dx} + P(x)y = Q(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.0574em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">Q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><p>通解：</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>y</mi><mo>=</mo><msup><mi>e</mi><mrow><mo>−</mo><mo>∫</mo><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow></msup><mo stretchy="false">(</mo><mo>∫</mo><mi>Q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>e</mi><mrow><mo>∫</mo><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow></msup><mi>d</mi><mi>x</mi><mo>+</mo><mi>C</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y = e^{-\int P(x)dx}(\int Q(x)e^{\int P(x)dx}dx + C) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.2222em;vertical-align:-0.8622em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.9765em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">−</span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mop op-symbol small-op mtight" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mathnormal mtight" style="margin-right:0.13889em;">P</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">Q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.9765em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mop op-symbol small-op mtight" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mathnormal mtight" style="margin-right:0.13889em;">P</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="mclose">)</span></span></span></span></span></p><h2 id="4-伯努利方程">4. 伯努利方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>y</mi><mo>=</mo><mi>Q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>y</mi><mi>n</mi></msup></mrow><annotation encoding="application/x-tex">y&#x27; + P(x)y = Q(x)y^n </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">Q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span></span></span></span></span></span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mrow><mi>d</mi><mi>y</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>+</mo><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>y</mi><mo>=</mo><mi>Q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>y</mi><mi>n</mi></msup></mrow><annotation encoding="application/x-tex">\frac{dy}{dx} + P(x)y = Q(x)y^n </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.0574em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">Q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span></span></span></span></span></span></span></span></span></span></p><p>令 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>u</mi><mo>=</mo><msup><mi>y</mi><mrow><mn>1</mn><mo>−</mo><mi>n</mi></mrow></msup></mrow><annotation encoding="application/x-tex">u = y^{1-n}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">u</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0085em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8141em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight">n</span></span></span></span></span></span></span></span></span></span></span></span>，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>y</mi><mo>=</mo><msup><mi>u</mi><mfrac><mn>1</mn><mrow><mn>1</mn><mo>−</mo><mi>n</mi></mrow></mfrac></msup></mrow><annotation encoding="application/x-tex">y = u^{\frac{1}{1-n}}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.9812em;"></span><span class="mord"><span class="mord mathnormal">u</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.9812em;"><span style="top:-3.3902em;margin-right:0.05em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mopen nulldelimiter sizing reset-size3 size6"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8443em;"><span style="top:-2.656em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight">n</span></span></span></span><span style="top:-3.2255em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line mtight" style="border-bottom-width:0.049em;"></span></span><span style="top:-3.384em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4035em;"><span></span></span></span></span></span><span class="mclose nulldelimiter sizing reset-size3 size6"></span></span></span></span></span></span></span></span></span></span></span></span></span>，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>=</mo><mfrac><mn>1</mn><mrow><mn>1</mn><mo>−</mo><mi>n</mi></mrow></mfrac><msup><mi>u</mi><mrow><mfrac><mn>1</mn><mrow><mn>1</mn><mo>−</mo><mi>n</mi></mrow></mfrac><mo>−</mo><mn>1</mn></mrow></msup><msup><mi>u</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup></mrow><annotation encoding="application/x-tex">y&#x27; = \frac{1}{1-n}u^{\frac{1}{1-n}-1}u&#x27;</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9463em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.3846em;vertical-align:-0.4033em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8451em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight">n</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4033em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">u</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.9812em;"><span style="top:-3.3902em;margin-right:0.05em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mopen nulldelimiter sizing reset-size3 size6"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8443em;"><span style="top:-2.656em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight">n</span></span></span></span><span style="top:-3.2255em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line mtight" style="border-bottom-width:0.049em;"></span></span><span style="top:-3.384em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4035em;"><span></span></span></span></span></span><span class="mclose nulldelimiter sizing reset-size3 size6"></span></span><span class="mbin mtight">−</span><span class="mord mtight">1</span></span></span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal">u</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mn>1</mn><mrow><mn>1</mn><mo>−</mo><mi>n</mi></mrow></mfrac><msup><mi>u</mi><mrow><mfrac><mn>1</mn><mrow><mn>1</mn><mo>−</mo><mi>n</mi></mrow></mfrac><mo>−</mo><mn>1</mn></mrow></msup><msup><mi>u</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>u</mi><mfrac><mn>1</mn><mrow><mn>1</mn><mo>−</mo><mi>n</mi></mrow></mfrac></msup><mo>=</mo><mi>Q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\frac{1}{1-n}u^{\frac{1}{1-n}-1}u&#x27; + P(x)u^{\frac{1}{1-n}} = Q(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.0908em;vertical-align:-0.7693em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal">n</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.7693em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">u</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:1.004em;"><span style="top:-3.413em;margin-right:0.05em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mopen nulldelimiter sizing reset-size3 size6"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8443em;"><span style="top:-2.656em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight">n</span></span></span></span><span style="top:-3.2255em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line mtight" style="border-bottom-width:0.049em;"></span></span><span style="top:-3.384em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4035em;"><span></span></span></span></span></span><span class="mclose nulldelimiter sizing reset-size3 size6"></span></span><span class="mbin mtight">−</span><span class="mord mtight">1</span></span></span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal">u</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.254em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal">u</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:1.004em;"><span style="top:-3.413em;margin-right:0.05em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mopen nulldelimiter sizing reset-size3 size6"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8443em;"><span style="top:-2.656em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight">n</span></span></span></span><span style="top:-3.2255em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line mtight" style="border-bottom-width:0.049em;"></span></span><span style="top:-3.384em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4035em;"><span></span></span></span></span></span><span class="mclose nulldelimiter sizing reset-size3 size6"></span></span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">Q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>u</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mo stretchy="false">(</mo><mn>1</mn><mo>−</mo><mi>n</mi><mo stretchy="false">)</mo><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>u</mi><mo>=</mo><mo stretchy="false">(</mo><mn>1</mn><mo>−</mo><mi>n</mi><mo stretchy="false">)</mo><mi>Q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">u&#x27; + (1-n)P(x)u = (1-n)Q(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8852em;vertical-align:-0.0833em;"></span><span class="mord"><span class="mord mathnormal">u</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">n</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">u</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">n</span><span class="mclose">)</span><span class="mord mathnormal">Q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><h2 id="5-全微分方程">5. 全微分方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>P</mi><mo stretchy="false">(</mo><mi>x</mi><mo separator="true">,</mo><mi>y</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>+</mo><mi>Q</mi><mo stretchy="false">(</mo><mi>x</mi><mo separator="true">,</mo><mi>y</mi><mo stretchy="false">)</mo><mi>d</mi><mi>y</mi><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">P(x,y)dx + Q(x,y)dy = 0 </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">Q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mrow><mi mathvariant="normal">∂</mi><mi>P</mi></mrow><mrow><mi mathvariant="normal">∂</mi><mi>y</mi></mrow></mfrac><mo>=</mo><mfrac><mrow><mi mathvariant="normal">∂</mi><mi>Q</mi></mrow><mrow><mi mathvariant="normal">∂</mi><mi>x</mi></mrow></mfrac></mrow><annotation encoding="application/x-tex">\frac{\partial P}{\partial y} = \frac{\partial Q}{\partial x} </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.2519em;vertical-align:-0.8804em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord" style="margin-right:0.05556em;">∂</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord" style="margin-right:0.05556em;">∂</span><span class="mord mathnormal" style="margin-right:0.13889em;">P</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.8804em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0574em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord" style="margin-right:0.05556em;">∂</span><span class="mord mathnormal">x</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord" style="margin-right:0.05556em;">∂</span><span class="mord mathnormal">Q</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p><h1>三、可降阶的高阶微分方程</h1><ol><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; = f(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><p>积分两次即可</p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>y</mi><mo separator="true">,</mo><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; = f(y,y&#x27;) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0519em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mclose">)</span></span></span></span></span></p><p>令 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>=</mo><mi>p</mi></mrow><annotation encoding="application/x-tex">y&#x27; = p</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9463em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">p</span></span></span></span>，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>=</mo><mfrac><mrow><mi>d</mi><mi>p</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>=</mo><mfrac><mrow><mi>d</mi><mi>p</mi></mrow><mrow><mi>d</mi><mi>y</mi></mrow></mfrac><mfrac><mrow><mi>d</mi><mi>y</mi></mrow><mrow><mi>d</mi><mi>x</mi></mrow></mfrac><mo>=</mo><mi>p</mi><mfrac><mrow><mi>d</mi><mi>p</mi></mrow><mrow><mi>d</mi><mi>y</mi></mrow></mfrac></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; = \frac{dp}{dx} = \frac{dp}{dy}\frac{dy}{dx} = p\frac{dp}{dy}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9463em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.2772em;vertical-align:-0.345em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9322em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.4461em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">p</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.4133em;vertical-align:-0.4811em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9322em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight" style="margin-right:0.03588em;">y</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.4461em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">p</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4811em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9322em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.4461em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight" style="margin-right:0.03588em;">y</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.4133em;vertical-align:-0.4811em;"></span><span class="mord mathnormal">p</span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9322em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight" style="margin-right:0.03588em;">y</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.4461em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">p</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4811em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span><br>化为可分离变量的微分方程</p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>y</mi><mo separator="true">,</mo><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; = f(y,y&#x27;) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0519em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mclose">)</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>=</mo><mi>p</mi><mspace width="1em"/><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>=</mo><mfrac><mrow><mi>d</mi><mi>p</mi></mrow><mrow><mi>d</mi><mi>y</mi></mrow></mfrac><mi>p</mi></mrow><annotation encoding="application/x-tex">y&#x27; = p \quad y&#x27;&#x27; = \frac{dp}{dy}p </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">p</span><span class="mspace" style="margin-right:1em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.2519em;vertical-align:-0.8804em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3714em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">d</span><span class="mord mathnormal">p</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.8804em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord mathnormal">p</span></span></span></span></span></p><p>化为可分离变量的微分方程</p></li></ol><h1>四、高阶线性微分方程</h1><h2 id="1-线性微分方程的解的结构">1. 线性微分方程的解的结构</h2><ul><li><p>齐次方程(1)：$$ y’’ + p(x)y’ + q(x)y = 0 $$</p></li><li><p>非齐次方程(2)：$$ y’’ + p(x)y’ + q(x)y = f(x) $$</p></li></ul><p><strong>定理一：</strong> 如果 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>y</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y_1(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 和 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>y</mi><mn>2</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y_2(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 是齐次方程(1)的两个线性无关的特解，那么 $$ y = C_1y_1(x) + C_2y_2(x) $$ 就是齐次方程的解。</p><p><strong>定理二：</strong> 如果 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>y</mi><mo>∗</mo></msup></mrow><annotation encoding="application/x-tex">y^*</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8831em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span></span></span></span></span></span></span></span> 是非齐次方程(2)的一个特解，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>y</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y_1(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 和 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>y</mi><mn>2</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y_2(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 是齐次方程(1)的两个线性无关的特解，那么</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>y</mi><mo>=</mo><msub><mi>C</mi><mn>1</mn></msub><msub><mi>y</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>+</mo><msub><mi>C</mi><mn>2</mn></msub><msub><mi>y</mi><mn>2</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>+</mo><msup><mi>y</mi><mo>∗</mo></msup></mrow><annotation encoding="application/x-tex">y = C_1y_1(x) + C_2y_2(x) + y^* </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0715em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0715em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.9331em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7387em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span></span></span></span></span></span></span></span></span></p><p>就是非齐次方程的解。</p><p><strong>定理三：</strong> 如果 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mi>y</mi><mn>1</mn><mo>∗</mo></msubsup></mrow><annotation encoding="application/x-tex">y_1^*</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9368em;vertical-align:-0.2481em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-2.4519em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2481em;"><span></span></span></span></span></span></span></span></span></span> 和 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mi>y</mi><mn>2</mn><mo>∗</mo></msubsup></mrow><annotation encoding="application/x-tex">y_2^*</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9368em;vertical-align:-0.2481em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-2.4519em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2481em;"><span></span></span></span></span></span></span></span></span></span> 分别是方程(2)和(1)的两个特解，那么 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mi>y</mi><mn>1</mn><mo>∗</mo></msubsup><mo>−</mo><msubsup><mi>y</mi><mn>2</mn><mo>∗</mo></msubsup></mrow><annotation encoding="application/x-tex">y_1^* - y_2^*</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9368em;vertical-align:-0.2481em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-2.4519em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2481em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.9368em;vertical-align:-0.2481em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-2.4519em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2481em;"><span></span></span></span></span></span></span></span></span></span> 是方程(1)的解。</p><p><strong>定理四：</strong> 如果 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mi>y</mi><mn>1</mn><mo>∗</mo></msubsup></mrow><annotation encoding="application/x-tex">y_1^*</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9368em;vertical-align:-0.2481em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-2.4519em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2481em;"><span></span></span></span></span></span></span></span></span></span> 和 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mi>y</mi><mn>2</mn><mo>∗</mo></msubsup></mrow><annotation encoding="application/x-tex">y_2^*</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9368em;vertical-align:-0.2481em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-2.4519em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2481em;"><span></span></span></span></span></span></span></span></span></span> 分别是方程</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>+</mo><mi>p</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mi>q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>y</mi><mo>=</mo><msub><mi>f</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; + p(x)y&#x27; + q(x)y = f_1(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.0519em;vertical-align:-0.25em;"></span><span class="mord mathnormal">p</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.1076em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><p>和</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>+</mo><mi>p</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mi>q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>y</mi><mo>=</mo><msub><mi>f</mi><mn>2</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; + p(x)y&#x27; + q(x)y = f_2(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.0519em;vertical-align:-0.25em;"></span><span class="mord mathnormal">p</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.1076em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><p>的特解，那么 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mi>y</mi><mn>1</mn><mo>∗</mo></msubsup><mo>+</mo><msubsup><mi>y</mi><mn>2</mn><mo>∗</mo></msubsup></mrow><annotation encoding="application/x-tex">y_1^* + y_2^*</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9368em;vertical-align:-0.2481em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-2.4519em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2481em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.9368em;vertical-align:-0.2481em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-2.4519em;margin-left:-0.0359em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2481em;"><span></span></span></span></span></span></span></span></span></span> 是方程</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>+</mo><mi>p</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mi>q</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>y</mi><mo>=</mo><msub><mi>f</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>+</mo><msub><mi>f</mi><mn>2</mn></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; + p(x)y&#x27; + q(x)y = f_1(x) + f_2(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.0519em;vertical-align:-0.25em;"></span><span class="mord mathnormal">p</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">q</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.1076em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.1076em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><p>的一个特解。</p><h2 id="2-常系数齐次线性微分方程">2. 常系数齐次线性微分方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>+</mo><mi>p</mi><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mi>q</mi><mi>y</mi><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; + py&#x27; + qy = 0 </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">p</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">q</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span></span></p><p><strong>特征方程：</strong> $$ r^2 + pr + q = 0 $$</p><p>设 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>r</mi><mn>1</mn></msub><mo separator="true">,</mo><msub><mi>r</mi><mn>2</mn></msub></mrow><annotation encoding="application/x-tex">r_1,r_2</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span> 是特征方程的根：</p><ol><li><p>不等实根 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>r</mi><mn>1</mn></msub><mo mathvariant="normal">≠</mo><msub><mi>r</mi><mn>2</mn></msub></mrow><annotation encoding="application/x-tex">r_1 \neq r_2</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel"><span class="mrel"><span class="mord vbox"><span class="thinbox"><span class="rlap"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="inner"><span class="mord"><span class="mrel"></span></span></span><span class="fix"></span></span></span></span></span><span class="mrel">=</span></span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.5806em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span>：$$ y = C_1e^{r_1x} + C_2e^{r_2x} $$</p></li><li><p>相等实根 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>r</mi><mn>1</mn></msub><mo>=</mo><msub><mi>r</mi><mn>2</mn></msub><mo>=</mo><mi>r</mi></mrow><annotation encoding="application/x-tex">r_1 = r_2 = r</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.5806em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.5806em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span></span></span></span>：$$ y = (C_1 + C_2x)e^{rx} $$</p></li><li><p>共轭复根 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>r</mi><mn>1</mn></msub><mo>=</mo><mi>α</mi><mo>+</mo><mi>i</mi><mi>β</mi><mo separator="true">,</mo><msub><mi>r</mi><mn>2</mn></msub><mo>=</mo><mi>α</mi><mo>−</mo><mi>i</mi><mi>β</mi></mrow><annotation encoding="application/x-tex">r_1 = \alpha + i\beta, r_2 = \alpha - i\beta</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.5806em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord mathnormal" style="margin-right:0.0037em;">α</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">i</span><span class="mord mathnormal" style="margin-right:0.05278em;">β</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord mathnormal" style="margin-right:0.0037em;">α</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">i</span><span class="mord mathnormal" style="margin-right:0.05278em;">β</span></span></span></span>：$$ y = e^{\alpha x}(C_1\cos\beta x + C_2\sin\beta x) $$</p></li></ol><h2 id="3-常系数非齐次线性微分方程">3. 常系数非齐次线性微分方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mo mathvariant="normal">′</mo></mrow></msup><mo>+</mo><mi>p</mi><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><mi>q</mi><mi>y</mi><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y&#x27;&#x27; + py&#x27; + qy = f(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.9963em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">p</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">q</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><ol><li><p>当 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><msub><mi>P</mi><mi>m</mi></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>e</mi><mrow><mi>λ</mi><mi>x</mi></mrow></msup></mrow><annotation encoding="application/x-tex">f(x) = P_m(x)e^{\lambda x}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0991em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.1389em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">m</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">λ</span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span></span></span></span> 时：</p><ul><li>令 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>y</mi><mo>∗</mo></msup><mo>=</mo><msup><mi>x</mi><mi>k</mi></msup><msub><mi>Q</mi><mi>m</mi></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>e</mi><mrow><mi>λ</mi><mi>x</mi></mrow></msup></mrow><annotation encoding="application/x-tex">y^* = x^kQ_m(x)e^{\lambda x}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8831em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0991em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03148em;">k</span></span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal">Q</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">m</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">λ</span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span></span></span></span></li><li><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>k</mi></mrow><annotation encoding="application/x-tex">k</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal" style="margin-right:0.03148em;">k</span></span></span></span> 是特征方程的根的重数</li><li><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>Q</mi><mi>m</mi></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">Q_m(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal">Q</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">m</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 是与 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>P</mi><mi>m</mi></msub><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">P_m(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.1389em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">m</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 同次的多项式</li></ul></li><li><p>当 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><msup><mi>e</mi><mrow><mi>λ</mi><mi>x</mi></mrow></msup><mo stretchy="false">[</mo><msubsup><mi>P</mi><mi>l</mi><mrow><mo stretchy="false">(</mo><mi>n</mi><mo stretchy="false">)</mo></mrow></msubsup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>cos</mi><mo>⁡</mo><mi>ω</mi><mi>x</mi><mo>+</mo><msub><mi>P</mi><mi>n</mi></msub><mo stretchy="false">(</mo><mi>x</mi><msup><mo stretchy="false">)</mo><mrow><mo stretchy="false">(</mo><mi>n</mi><mo stretchy="false">)</mo></mrow></msup><mi>sin</mi><mo>⁡</mo><mi>ω</mi><mi>x</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">f(x) = e^{\lambda x}[P_l^{(n)}(x)\cos\omega x + P_n(x)^{(n)}\sin\omega x]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.3461em;vertical-align:-0.3013em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">λ</span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span><span class="mopen">[</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0448em;"><span style="top:-2.3987em;margin-left:-0.1389em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.01968em;">l</span></span></span><span style="top:-3.2198em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mopen mtight">(</span><span class="mord mathnormal mtight">n</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3013em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">ω</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.138em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.1389em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose"><span class="mclose">)</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.888em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mopen mtight">(</span><span class="mord mathnormal mtight">n</span><span class="mclose mtight">)</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">ω</span><span class="mord mathnormal">x</span><span class="mclose">]</span></span></span></span> 时：</p><ul><li>令 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>y</mi><mo>∗</mo></msup><mo>=</mo><msup><mi>x</mi><mi>k</mi></msup><msup><mi>e</mi><mrow><mi>α</mi><mi>x</mi></mrow></msup><mo stretchy="false">[</mo><msubsup><mi>R</mi><mi>m</mi><mrow><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></msubsup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>cos</mi><mo>⁡</mo><mi>β</mi><mi>x</mi><mo>+</mo><msubsup><mi>R</mi><mi>m</mi><mrow><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo></mrow></msubsup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>sin</mi><mo>⁡</mo><mi>β</mi><mi>x</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">y^* = x^ke^{\alpha x}[R_m^{(1)}(x)\cos\beta x + R_m^{(2)}(x)\sin\beta x]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8831em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6887em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mbin mtight">∗</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.2948em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03148em;">k</span></span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6644em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">αx</span></span></span></span></span></span></span></span></span><span class="mopen">[</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.00773em;">R</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0448em;"><span style="top:-2.5834em;margin-left:-0.0077em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">m</span></span></span><span style="top:-3.2198em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mopen mtight">(</span><span class="mord mtight">1</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.1166em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05278em;">β</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.2948em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.00773em;">R</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0448em;"><span style="top:-2.5834em;margin-left:-0.0077em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">m</span></span></span><span style="top:-3.2198em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mopen mtight">(</span><span class="mord mtight">2</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.1166em;"><span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05278em;">β</span><span class="mord mathnormal">x</span><span class="mclose">]</span></span></span></span></li><li><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>m</mi><mo>=</mo><mi>max</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>l</mi><mo separator="true">,</mo><mi>n</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">m = \max(l,n)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">m</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">max</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">n</span><span class="mclose">)</span></span></span></span></li></ul></li></ol><h2 id="4-欧拉方程">4. 欧拉方程</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>x</mi><mi>n</mi></msup><msup><mi>y</mi><mrow><mo stretchy="false">(</mo><mi>n</mi><mo stretchy="false">)</mo></mrow></msup><mo>+</mo><msub><mi>a</mi><mn>1</mn></msub><msup><mi>x</mi><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msup><msup><mi>y</mi><mrow><mo stretchy="false">(</mo><mi>n</mi><mo>−</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></msup><mo>+</mo><mo>⋯</mo><mo>+</mo><msub><mi>a</mi><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msub><mi>x</mi><msup><mi>y</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo>+</mo><msub><mi>a</mi><mi>n</mi></msub><mi>y</mi><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">x^ny^{(n)} + a_1x^{n-1}y^{(n-1)} + \cdots + a_{n-1}xy&#x27; + a_ny = f(x) </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.1324em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.938em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mopen mtight">(</span><span class="mord mathnormal mtight">n</span><span class="mclose mtight">)</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.1324em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal">a</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">n</span><span class="mbin mtight">−</span><span class="mord mtight">1</span></span></span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.938em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mopen mtight">(</span><span class="mord mathnormal mtight">n</span><span class="mbin mtight">−</span><span class="mord mtight">1</span><span class="mclose mtight">)</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="minner">⋯</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.0102em;vertical-align:-0.2083em;"></span><span class="mord"><span class="mord mathnormal">a</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">n</span><span class="mbin mtight">−</span><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2083em;"><span></span></span></span></span></span></span><span class="mord mathnormal">x</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal">a</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span></span></p><p>令 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>x</mi><mo>=</mo><msup><mi>e</mi><mi>t</mi></msup></mrow><annotation encoding="application/x-tex">x = e^t</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7936em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7936em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">t</span></span></span></span></span></span></span></span></span></span></span>，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>t</mi><mo>=</mo><mi>ln</mi><mo>⁡</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">t = \ln x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6151em;"></span><span class="mord mathnormal">t</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mop">ln</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span></span></span></span>，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>D</mi><mo>=</mo><mfrac><mi>d</mi><mrow><mi>d</mi><mi>t</mi></mrow></mfrac></mrow><annotation encoding="application/x-tex">D = \frac{d}{dt}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">D</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.2251em;vertical-align:-0.345em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8801em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mathnormal mtight">t</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span>，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>D</mi><mi>k</mi></msup><mo>=</mo><mfrac><msup><mi>d</mi><mi>k</mi></msup><mrow><mi>d</mi><msup><mi>t</mi><mi>k</mi></msup></mrow></mfrac></mrow><annotation encoding="application/x-tex">D^k = \frac{d^k}{dt^k}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8491em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">D</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03148em;">k</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.4003em;vertical-align:-0.3574em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0429em;"><span style="top:-2.6426em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="mord mtight"><span class="mord mathnormal mtight">t</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.782em;"><span style="top:-2.786em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03148em;">k</span></span></span></span></span></span></span></span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight">d</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.927em;"><span style="top:-2.931em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03148em;">k</span></span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3574em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>x</mi><mi>k</mi></msup><msup><mi>y</mi><mrow><mo stretchy="false">(</mo><mi>k</mi><mo stretchy="false">)</mo></mrow></msup><mo>=</mo><mi>D</mi><mo stretchy="false">(</mo><mi>D</mi><mo>−</mo><mn>1</mn><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mi>D</mi><mo>−</mo><mn>2</mn><mo stretchy="false">)</mo><mo>⋯</mo><mo stretchy="false">(</mo><mi>D</mi><mo>−</mo><mi>k</mi><mo>+</mo><mn>1</mn><mo stretchy="false">)</mo><mi>y</mi></mrow><annotation encoding="application/x-tex">x^ky^{(k)} = D(D-1)(D-2)\cdots(D-k+1)y </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.1324em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8991em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03148em;">k</span></span></span></span></span></span></span></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.938em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mopen mtight">(</span><span class="mord mathnormal mtight" style="margin-right:0.03148em;">k</span><span class="mclose mtight">)</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">D</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">D</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">1</span><span class="mclose">)</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">D</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">2</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="minner">⋯</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">D</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.7778em;vertical-align:-0.0833em;"></span><span class="mord mathnormal" style="margin-right:0.03148em;">k</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">1</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span></span></p><p>化为常系数线性微分方程。</p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;一、常微分方程的概念&lt;/h1&gt;
&lt;h2 id=&quot;1-微分方程&quot;&gt;1. 微分方程&lt;/h2&gt;
&lt;p&gt;&lt;span class=&quot;katex-display&quot;&gt;&lt;span class=&quot;katex&quot;&gt;&lt;span class=&quot;katex-mathml&quot;&gt;&lt;math xmlns=&quot;</summary>
      
    
    
    
    
    <category term="高数" scheme="http://example.com/tags/%E9%AB%98%E6%95%B0/"/>
    
  </entry>
  
  <entry>
    <title>定积分的应用</title>
    <link href="http://example.com/post/fc35c9de.html"/>
    <id>http://example.com/post/fc35c9de.html</id>
    <published>2025-03-31T12:52:22.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>一、几何应用</h1><h2 id="1-平面图形的面积">1. 平面图形的面积</h2><p>(1) 若平面域D由曲线<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>y</mi><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>y</mi><mo>=</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>≥</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo stretchy="false">)</mo><mtext>，</mtext><mi>x</mi><mo>=</mo><mi>a</mi><mo separator="true">,</mo><mi>x</mi><mo>=</mo><mi>b</mi><mo stretchy="false">(</mo><mi>a</mi><mo>&lt;</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y=f(x),y=g(x)(f(x)\geq g(x))，x=a,x=b(a&lt;b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≥</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">))</span><span class="mord cjk_fallback">，</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">b</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>围成，则D的面积为</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>A</mi><mo>=</mo><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mo stretchy="false">[</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>−</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">A=\int_a^b[f(x)-g(x)]dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">b</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mopen">[</span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)]</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><p>(2) 若平面域D由曲线$ \rho=f(\theta), \theta=\alpha, \theta=\beta(\alpha&lt;\beta)$围成，则D的面积为</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>S</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><msubsup><mo>∫</mo><mi>α</mi><mi>β</mi></msubsup><msup><mi>f</mi><mn>2</mn></msup><mo stretchy="false">(</mo><mi>θ</mi><mo stretchy="false">)</mo><mi>d</mi><mi>θ</mi></mrow><annotation encoding="application/x-tex">S=\frac{1}{2}\int_{\alpha}^{\beta}f^2(\theta)d\theta</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.05764em;">S</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.0037em;">α</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.05278em;">β</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span></span></span></span></span></p><p>总结为 $$ S=\int\int_D 1 dA $$</p><h2 id="2-旋转体的体积">2. 旋转体的体积</h2><p>(1) 若平面域D由曲线<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>y</mi><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mo stretchy="false">(</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>&gt;</mo><mo>=</mo><mn>0</mn><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">y=f(x),(f(x)&gt;=0)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">0</span><span class="mclose">)</span></span></span></span>，直线<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>x</mi><mo>=</mo><mi>a</mi><mo separator="true">,</mo><mi>x</mi><mo>=</mo><mi>b</mi><mo stretchy="false">(</mo><mi>a</mi><mo>&lt;</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">x=a,x=b(a&lt;b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">b</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>及x轴围成，则<br>(1)区域D绕x轴旋转一周所形成的旋转体的体积为</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msub><mi>V</mi><mi>x</mi></msub><mo>=</mo><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>π</mi><msup><mi>f</mi><mn>2</mn></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">V_x=\int_a^b\pi f^2(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.22222em;">V</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.2222em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">x</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">b</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">π</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><p>(2) 区域D绕y轴旋转一周所形成的旋转体的体积为</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msub><mi>V</mi><mi>y</mi></msub><mo>=</mo><mn>2</mn><mi>π</mi><msubsup><mo>∫</mo><mi>c</mi><mi>d</mi></msubsup><mi>x</mi><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">V_y=2\pi \int_c^d x f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9694em;vertical-align:-0.2861em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.22222em;">V</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.2222em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">y</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2861em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mord">2</span><span class="mord mathnormal" style="margin-right:0.03588em;">π</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">c</span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">d</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><p>在更一般的情况下,区域D绕直线L旋转一周所形成的旋转体的体积计算</p><p>取D中一点微元(x,y),与直线L的距离为<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>r</mi><mo stretchy="false">(</mo><mi>x</mi><mo separator="true">,</mo><mi>y</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">r(x,y)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span></span></span></span>,则旋转体的体积为</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>V</mi><mo>=</mo><mn>2</mn><mi>π</mi><mo>∫</mo><msub><mo>∫</mo><mi>D</mi></msub><mi>r</mi><mo stretchy="false">(</mo><mi>x</mi><mo separator="true">,</mo><mi>y</mi><mo stretchy="false">)</mo><mi>d</mi><mi>s</mi></mrow><annotation encoding="application/x-tex">V=2\pi\int\int_D r(x,y)ds</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.22222em;">V</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.2719em;vertical-align:-0.9119em;"></span><span class="mord">2</span><span class="mord mathnormal" style="margin-right:0.03588em;">π</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:-0.4336em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.02778em;">D</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">s</span></span></span></span></span></p><p>其中$$r(x,y)=\frac{|ax+by+c|}{\sqrt{a^2+b^2}}$$</p><h2 id="3-曲线弧长">3. 曲线弧长</h2><p>(1)<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>C</mi><mo>:</mo><mi>y</mi><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>a</mi><mo>≤</mo><mi>x</mi><mo>≤</mo><mi>b</mi></mrow><annotation encoding="application/x-tex">C : y=f(x),a\leq x\leq b</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">:</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">a</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7719em;vertical-align:-0.136em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">b</span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>S</mi><mo>=</mo><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><msqrt><mrow><mn>1</mn><mo>+</mo><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mn>2</mn></mrow></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></msqrt><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">S=\int_a^b\sqrt{1+y&#x27;^2(x)}dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.05764em;">S</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">b</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord sqrt"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9839em;"><span class="svg-align" style="top:-3.2em;"><span class="pstrut" style="height:3.2em;"></span><span class="mord" style="padding-left:1em;"><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′2</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span><span style="top:-2.9439em;"><span class="pstrut" style="height:3.2em;"></span><span class="hide-tail" style="min-width:1.02em;height:1.28em;"><svg xmlns="http://www.w3.org/2000/svg" width="400em" height="1.28em" viewBox="0 0 400000 1296" preserveAspectRatio="xMinYMin slice"><path d="M263,681c0.7,0,18,39.7,52,119c34,79.3,68.167,158.7,102.5,238c34.3,79.3,51.8,119.3,52.5,120c340,-704.7,510.7,-1060.3,512,-1067l0 -0c4.7,-7.3,11,-11,19,-11H40000v40H1012.3s-271.3,567,-271.3,567c-38.7,80.7,-84,175,-136,283c-52,108,-89.167,185.3,-111.5,232c-22.3,46.7,-33.8,70.3,-34.5,71c-4.7,4.7,-12.3,7,-23,7s-12,-1,-12,-1s-109,-253,-109,-253c-72.7,-168,-109.3,-252,-110,-252c-10.7,8,-22,16.7,-34,26c-22,17.3,-33.3,26,-34,26s-26,-26,-26,-26s76,-59,76,-59s76,-60,76,-60zM1001 80h400000v40h-400000z"/></svg></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2561em;"><span></span></span></span></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><p>(2)<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>C</mi><mo>:</mo><mi>x</mi><mo>=</mo><mi>x</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>y</mi><mo>=</mo><mi>y</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>t</mi><mo>∈</mo><mo stretchy="false">[</mo><mi>α</mi><mo separator="true">,</mo><mi>β</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">C : x=x(t),y=y(t),t\in[\alpha,\beta]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">:</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">x</span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">t</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal" style="margin-right:0.0037em;">α</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05278em;">β</span><span class="mclose">]</span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>S</mi><mo>=</mo><msubsup><mo>∫</mo><mi>α</mi><mi>β</mi></msubsup><msqrt><mrow><msup><mi>x</mi><mrow><mo mathvariant="normal">′</mo><mn>2</mn></mrow></msup><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo><mo>+</mo><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mn>2</mn></mrow></msup><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></mrow></msqrt><mi>d</mi><mi>t</mi></mrow><annotation encoding="application/x-tex">S=\int_{\alpha}^{\beta}\sqrt{x&#x27;^2(t)+y&#x27;^2(t)}dt</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.05764em;">S</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.0037em;">α</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.05278em;">β</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord sqrt"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9839em;"><span class="svg-align" style="top:-3.2em;"><span class="pstrut" style="height:3.2em;"></span><span class="mord" style="padding-left:1em;"><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′2</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′2</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span></span></span><span style="top:-2.9439em;"><span class="pstrut" style="height:3.2em;"></span><span class="hide-tail" style="min-width:1.02em;height:1.28em;"><svg xmlns="http://www.w3.org/2000/svg" width="400em" height="1.28em" viewBox="0 0 400000 1296" preserveAspectRatio="xMinYMin slice"><path d="M263,681c0.7,0,18,39.7,52,119c34,79.3,68.167,158.7,102.5,238c34.3,79.3,51.8,119.3,52.5,120c340,-704.7,510.7,-1060.3,512,-1067l0 -0c4.7,-7.3,11,-11,19,-11H40000v40H1012.3s-271.3,567,-271.3,567c-38.7,80.7,-84,175,-136,283c-52,108,-89.167,185.3,-111.5,232c-22.3,46.7,-33.8,70.3,-34.5,71c-4.7,4.7,-12.3,7,-23,7s-12,-1,-12,-1s-109,-253,-109,-253c-72.7,-168,-109.3,-252,-110,-252c-10.7,8,-22,16.7,-34,26c-22,17.3,-33.3,26,-34,26s-26,-26,-26,-26s76,-59,76,-59s76,-60,76,-60zM1001 80h400000v40h-400000z"/></svg></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2561em;"><span></span></span></span></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal">t</span></span></span></span></span></p><p>(3)<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>C</mi><mo>:</mo><mi>ρ</mi><mo>=</mo><mi>ρ</mi><mo stretchy="false">(</mo><mi>θ</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>θ</mi><mo>∈</mo><mo stretchy="false">[</mo><mi>α</mi><mo separator="true">,</mo><mi>β</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">C : \rho=\rho(\theta),\theta\in[\alpha,\beta]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">:</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">ρ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">ρ</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal" style="margin-right:0.0037em;">α</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05278em;">β</span><span class="mclose">]</span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>S</mi><mo>=</mo><msubsup><mo>∫</mo><mi>α</mi><mi>β</mi></msubsup><msqrt><mrow><msup><mi>ρ</mi><mn>2</mn></msup><mo stretchy="false">(</mo><mi>θ</mi><mo stretchy="false">)</mo><mo>+</mo><msup><mi>ρ</mi><mrow><mo mathvariant="normal">′</mo><mn>2</mn></mrow></msup><mo stretchy="false">(</mo><mi>θ</mi><mo stretchy="false">)</mo></mrow></msqrt><mi>d</mi><mi>θ</mi></mrow><annotation encoding="application/x-tex">S=\int_{\alpha}^{\beta}\sqrt{\rho^2(\theta)+\rho&#x27;^2(\theta)}d\theta</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.05764em;">S</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.0037em;">α</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.05278em;">β</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord sqrt"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9839em;"><span class="svg-align" style="top:-3.2em;"><span class="pstrut" style="height:3.2em;"></span><span class="mord" style="padding-left:1em;"><span class="mord"><span class="mord mathnormal">ρ</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord"><span class="mord mathnormal">ρ</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′2</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mclose">)</span></span></span><span style="top:-2.9439em;"><span class="pstrut" style="height:3.2em;"></span><span class="hide-tail" style="min-width:1.02em;height:1.28em;"><svg xmlns="http://www.w3.org/2000/svg" width="400em" height="1.28em" viewBox="0 0 400000 1296" preserveAspectRatio="xMinYMin slice"><path d="M263,681c0.7,0,18,39.7,52,119c34,79.3,68.167,158.7,102.5,238c34.3,79.3,51.8,119.3,52.5,120c340,-704.7,510.7,-1060.3,512,-1067l0 -0c4.7,-7.3,11,-11,19,-11H40000v40H1012.3s-271.3,567,-271.3,567c-38.7,80.7,-84,175,-136,283c-52,108,-89.167,185.3,-111.5,232c-22.3,46.7,-33.8,70.3,-34.5,71c-4.7,4.7,-12.3,7,-23,7s-12,-1,-12,-1s-109,-253,-109,-253c-72.7,-168,-109.3,-252,-110,-252c-10.7,8,-22,16.7,-34,26c-22,17.3,-33.3,26,-34,26s-26,-26,-26,-26s76,-59,76,-59s76,-60,76,-60zM1001 80h400000v40h-400000z"/></svg></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2561em;"><span></span></span></span></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span></span></span></span></span></p><h2 id="4-旋转体的侧面积">4. 旋转体的侧面积</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>S</mi><mo>=</mo><mn>2</mn><mi>π</mi><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msqrt><mrow><mn>1</mn><mo>+</mo><msup><mi>f</mi><mrow><mo mathvariant="normal">′</mo><mn>2</mn></mrow></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></msqrt><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">S = 2\pi\int_a^b f(x)\sqrt{1+f&#x27;^2(x)}dx </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.05764em;">S</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mord">2</span><span class="mord mathnormal" style="margin-right:0.03588em;">π</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">b</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord sqrt"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9839em;"><span class="svg-align" style="top:-3.2em;"><span class="pstrut" style="height:3.2em;"></span><span class="mord" style="padding-left:1em;"><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′2</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span><span style="top:-2.9439em;"><span class="pstrut" style="height:3.2em;"></span><span class="hide-tail" style="min-width:1.02em;height:1.28em;"><svg xmlns="http://www.w3.org/2000/svg" width="400em" height="1.28em" viewBox="0 0 400000 1296" preserveAspectRatio="xMinYMin slice"><path d="M263,681c0.7,0,18,39.7,52,119c34,79.3,68.167,158.7,102.5,238c34.3,79.3,51.8,119.3,52.5,120c340,-704.7,510.7,-1060.3,512,-1067l0 -0c4.7,-7.3,11,-11,19,-11H40000v40H1012.3s-271.3,567,-271.3,567c-38.7,80.7,-84,175,-136,283c-52,108,-89.167,185.3,-111.5,232c-22.3,46.7,-33.8,70.3,-34.5,71c-4.7,4.7,-12.3,7,-23,7s-12,-1,-12,-1s-109,-253,-109,-253c-72.7,-168,-109.3,-252,-110,-252c-10.7,8,-22,16.7,-34,26c-22,17.3,-33.3,26,-34,26s-26,-26,-26,-26s76,-59,76,-59s76,-60,76,-60zM1001 80h400000v40h-400000z"/></svg></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2561em;"><span></span></span></span></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>S</mi><mo>=</mo><mn>2</mn><mi>π</mi><msubsup><mo>∫</mo><mi>α</mi><mi>β</mi></msubsup><mi>y</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo><msqrt><mrow><msup><mi>x</mi><mrow><mo mathvariant="normal">′</mo><mn>2</mn></mrow></msup><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo><mo>+</mo><msup><mi>y</mi><mrow><mo mathvariant="normal">′</mo><mn>2</mn></mrow></msup><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></mrow></msqrt><mi>d</mi><mi>t</mi></mrow><annotation encoding="application/x-tex">S = 2\pi\int_{\alpha}^{\beta} y(t)\sqrt{x&#x27;^2(t)+y&#x27;^2(t)}dt </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.05764em;">S</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mord">2</span><span class="mord mathnormal" style="margin-right:0.03588em;">π</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.0037em;">α</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.05278em;">β</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span><span class="mord sqrt"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9839em;"><span class="svg-align" style="top:-3.2em;"><span class="pstrut" style="height:3.2em;"></span><span class="mord" style="padding-left:1em;"><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′2</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′2</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span></span></span><span style="top:-2.9439em;"><span class="pstrut" style="height:3.2em;"></span><span class="hide-tail" style="min-width:1.02em;height:1.28em;"><svg xmlns="http://www.w3.org/2000/svg" width="400em" height="1.28em" viewBox="0 0 400000 1296" preserveAspectRatio="xMinYMin slice"><path d="M263,681c0.7,0,18,39.7,52,119c34,79.3,68.167,158.7,102.5,238c34.3,79.3,51.8,119.3,52.5,120c340,-704.7,510.7,-1060.3,512,-1067l0 -0c4.7,-7.3,11,-11,19,-11H40000v40H1012.3s-271.3,567,-271.3,567c-38.7,80.7,-84,175,-136,283c-52,108,-89.167,185.3,-111.5,232c-22.3,46.7,-33.8,70.3,-34.5,71c-4.7,4.7,-12.3,7,-23,7s-12,-1,-12,-1s-109,-253,-109,-253c-72.7,-168,-109.3,-252,-110,-252c-10.7,8,-22,16.7,-34,26c-22,17.3,-33.3,26,-34,26s-26,-26,-26,-26s76,-59,76,-59s76,-60,76,-60zM1001 80h400000v40h-400000z"/></svg></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2561em;"><span></span></span></span></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal">t</span></span></span></span></span></p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>S</mi><mo>=</mo><mn>2</mn><mi>π</mi><msubsup><mo>∫</mo><mi>α</mi><mi>β</mi></msubsup><mi>ρ</mi><mi>sin</mi><mo>⁡</mo><mi>θ</mi><msqrt><mrow><msup><mi>ρ</mi><mn>2</mn></msup><mo stretchy="false">(</mo><mi>θ</mi><mo stretchy="false">)</mo><mo>+</mo><msup><mi>ρ</mi><mrow><mo mathvariant="normal">′</mo><mn>2</mn></mrow></msup><mo stretchy="false">(</mo><mi>θ</mi><mo stretchy="false">)</mo></mrow></msqrt><mi>d</mi><mi>θ</mi></mrow><annotation encoding="application/x-tex">S = 2\pi\int_{\alpha}^{\beta} \rho\sin \theta \sqrt{\rho^2(\theta)+\rho&#x27;^2(\theta)}d\theta </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.05764em;">S</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mord">2</span><span class="mord mathnormal" style="margin-right:0.03588em;">π</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.0037em;">α</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.05278em;">β</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">ρ</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mord sqrt"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9839em;"><span class="svg-align" style="top:-3.2em;"><span class="pstrut" style="height:3.2em;"></span><span class="mord" style="padding-left:1em;"><span class="mord"><span class="mord mathnormal">ρ</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord"><span class="mord mathnormal">ρ</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7401em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′2</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mclose">)</span></span></span><span style="top:-2.9439em;"><span class="pstrut" style="height:3.2em;"></span><span class="hide-tail" style="min-width:1.02em;height:1.28em;"><svg xmlns="http://www.w3.org/2000/svg" width="400em" height="1.28em" viewBox="0 0 400000 1296" preserveAspectRatio="xMinYMin slice"><path d="M263,681c0.7,0,18,39.7,52,119c34,79.3,68.167,158.7,102.5,238c34.3,79.3,51.8,119.3,52.5,120c340,-704.7,510.7,-1060.3,512,-1067l0 -0c4.7,-7.3,11,-11,19,-11H40000v40H1012.3s-271.3,567,-271.3,567c-38.7,80.7,-84,175,-136,283c-52,108,-89.167,185.3,-111.5,232c-22.3,46.7,-33.8,70.3,-34.5,71c-4.7,4.7,-12.3,7,-23,7s-12,-1,-12,-1s-109,-253,-109,-253c-72.7,-168,-109.3,-252,-110,-252c-10.7,8,-22,16.7,-34,26c-22,17.3,-33.3,26,-34,26s-26,-26,-26,-26s76,-59,76,-59s76,-60,76,-60zM1001 80h400000v40h-400000z"/></svg></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2561em;"><span></span></span></span></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span></span></span></span></span></p><h1>二、物理应用</h1>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;一、几何应用&lt;/h1&gt;
&lt;h2 id=&quot;1-平面图形的面积&quot;&gt;1. 平面图形的面积&lt;/h2&gt;
&lt;p&gt;(1) 若平面域D由曲线&lt;span class=&quot;katex&quot;&gt;&lt;span class=&quot;katex-mathml&quot;&gt;&lt;math xmlns=&quot;http://www.w3.</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>反常积分</title>
    <link href="http://example.com/post/becfbefc.html"/>
    <id>http://example.com/post/becfbefc.html</id>
    <published>2025-03-29T16:00:00.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>一、无穷区间上的反常积分</h1><h2 id="定义1">定义1</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><munder><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>b</mi><mo>→</mo><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></munder><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}f(x)dx = \lim_{b\to+\infty}\int_{a}^{b}f(x)dx </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.4332em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.5212em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop op-limits"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6944em;"><span style="top:-2.3479em;margin-left:0em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span><span class="mrel mtight">→</span><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span><span style="top:-3em;"><span class="pstrut" style="height:3em;"></span><span><span class="mop">lim</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.8104em;"><span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><h2 id="定义2">定义2</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msubsup><mo>∫</mo><mrow><mo>−</mo><mi mathvariant="normal">∞</mi></mrow><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><munder><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>a</mi><mo>→</mo><mo>−</mo><mi mathvariant="normal">∞</mi></mrow></munder><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{-\infty}^{b}f(x)dx = \lim_{a\to-\infty}\int_{a}^{b}f(x)dx </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.5693em;vertical-align:-0.9703em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">−</span><span class="mord mtight">∞</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9703em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop op-limits"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6944em;"><span style="top:-2.4em;margin-left:0em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span><span class="mrel mtight">→</span><span class="mord mtight">−</span><span class="mord mtight">∞</span></span></span></span><span style="top:-3em;"><span class="pstrut" style="height:3em;"></span><span><span class="mop">lim</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.7583em;"><span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><h2 id="定义3">定义3</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msubsup><mo>∫</mo><mrow><mo>−</mo><mi mathvariant="normal">∞</mi></mrow><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><msubsup><mo>∫</mo><mrow><mo>−</mo><mi mathvariant="normal">∞</mi></mrow><mi>c</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>+</mo><msubsup><mo>∫</mo><mi>c</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{-\infty}^{+\infty}f(x)dx = \int_{-\infty}^{c}f(x)dx + \int_{c}^{+\infty}f(x)dx </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.4915em;vertical-align:-0.9703em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.5212em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">−</span><span class="mord mtight">∞</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9703em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.3846em;vertical-align:-0.9703em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.4143em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">−</span><span class="mord mtight">∞</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">c</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9703em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.4332em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.5212em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">c</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><h2 id="定理1-比较判别法">定理1 比较判别法</h2><p>设 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x),g(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mo>+</mo><mi mathvariant="normal">∞</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">[a,+\infty)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord">+</span><span class="mord">∞</span><span class="mclose">)</span></span></span></span> 上连续，且 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>0</mn><mo>≤</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>≤</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">0\leq f(x)\leq g(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7804em;vertical-align:-0.136em;"></span><span class="mord">0</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>,则</p><ol><li>若 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 收敛，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 收敛</li><li>若 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 发散，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 发散</li></ol><h2 id="定理2-极限判别法">定理2 极限判别法</h2><p>设 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x),g(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mo>+</mo><mi mathvariant="normal">∞</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">[a,+\infty)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord">+</span><span class="mord">∞</span><span class="mclose">)</span></span></span></span> 上非负连续，且<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msub><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mrow><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><mi>λ</mi></mrow><annotation encoding="application/x-tex">\lim_{x\to+\infty}\frac{f(x)}{g(x)}= \lambda</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.53em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.2583em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2083em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.01em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">λ</span></span></span></span></p><ol><li>当 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>λ</mi><mo>&gt;</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\lambda &gt; 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7335em;vertical-align:-0.0391em;"></span><span class="mord mathnormal">λ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span> 时，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 与 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 同敛散</li><li>当 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>λ</mi><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\lambda=0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">λ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span> 时，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 收敛，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 收敛</li><li>当 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>λ</mi><mo>=</mo><mo>+</mo><mi mathvariant="normal">∞</mi></mrow><annotation encoding="application/x-tex">\lambda=+\infty</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">λ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord">+</span><span class="mord">∞</span></span></span></span> 时，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 发散，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3221em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.9662em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span> 发散</li></ol><h2 id="常用结论">常用结论</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mrow><mo>+</mo><mi mathvariant="normal">∞</mi></mrow></msubsup><mfrac><mn>1</mn><msup><mi>x</mi><mi>p</mi></msup></mfrac><mi>d</mi><mi>x</mi><mrow><mo fence="true">{</mo><mtable rowspacing="0.36em" columnalign="left left" columnspacing="1em"><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mrow><mi>p</mi><mo>&gt;</mo><mn>1</mn><mo separator="true">,</mo></mrow></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mtext>收敛</mtext></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mrow><mi>p</mi><mo>≤</mo><mn>1</mn><mo separator="true">,</mo></mrow></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mtext>发散</mtext></mstyle></mtd></mtr></mtable></mrow><mo stretchy="false">(</mo><mi>a</mi><mo>&gt;</mo><mn>0</mn><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\int_{a}^{+\infty}\frac{1}{x^p}dx \begin{cases} p&gt;1, &amp; 收敛 \\ p\leq 1, &amp; 发散   \end{cases} (a&gt;0)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:3em;vertical-align:-1.25em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.5212em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">+</span><span class="mord mtight">∞</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.5904em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">p</span></span></span></span></span></span></span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="minner"><span class="mopen delimcenter" style="top:0em;"><span class="delimsizing size4">{</span></span><span class="mord"><span class="mtable"><span class="col-align-l"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.69em;"><span style="top:-3.69em;"><span class="pstrut" style="height:3.008em;"></span><span class="mord"><span class="mord mathnormal">p</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mord">1</span><span class="mpunct">,</span></span></span><span style="top:-2.25em;"><span class="pstrut" style="height:3.008em;"></span><span class="mord"><span class="mord mathnormal">p</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mord">1</span><span class="mpunct">,</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:1.19em;"><span></span></span></span></span></span><span class="arraycolsep" style="width:1em;"></span><span class="col-align-l"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.69em;"><span style="top:-3.69em;"><span class="pstrut" style="height:3.008em;"></span><span class="mord"><span class="mord cjk_fallback">收敛</span></span></span><span style="top:-2.25em;"><span class="pstrut" style="height:3.008em;"></span><span class="mord"><span class="mord cjk_fallback">发散</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:1.19em;"><span></span></span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">0</span><span class="mclose">)</span></span></span></span></span></p><h1>二、无界函数的反常积分</h1><h2 id="定义1-2">定义1</h2><p>设点a是函数<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>的瑕点</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><munder><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>t</mi><mo>→</mo><mi>a</mi><mo>+</mo></mrow></munder><msubsup><mo>∫</mo><mi>t</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}f(x)dx = \lim_{t\to a+}\int_{t}^{b}f(x)dx </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop op-limits"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6944em;"><span style="top:-2.4em;margin-left:0em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">t</span><span class="mrel mtight">→</span><span class="mord mathnormal mtight">a</span><span class="mord mtight">+</span></span></span></span><span style="top:-3em;"><span class="pstrut" style="height:3em;"></span><span><span class="mop">lim</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.7583em;"><span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">t</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><h2 id="定义2-2">定义2</h2><p>设点b是函数<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>的瑕点</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><munder><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>t</mi><mo>→</mo><mi>b</mi><mo>−</mo></mrow></munder><msubsup><mo>∫</mo><mi>a</mi><mi>t</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}f(x)dx = \lim_{t\to b-}\int_{a}^{t}f(x)dx </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.4554em;vertical-align:-0.9119em;"></span><span class="mop op-limits"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6944em;"><span style="top:-2.3479em;margin-left:0em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">t</span><span class="mrel mtight">→</span><span class="mord mathnormal mtight">b</span><span class="mord mtight">−</span></span></span></span><span style="top:-3em;"><span class="pstrut" style="height:3em;"></span><span><span class="mop">lim</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.8104em;"><span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.5435em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">t</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><h2 id="定义3-2">定义3</h2><p>设点c是函数<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>的瑕点(a&lt;c&lt;b)</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><msubsup><mo>∫</mo><mi>a</mi><mi>c</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>+</mo><msubsup><mo>∫</mo><mi>c</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}f(x)dx = \int_{a}^{c}f(x)dx + \int_{c}^{b}f(x)dx </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.3262em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.4143em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">c</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.511em;vertical-align:-0.9119em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">c</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p><h2 id="定理1-比较判别法-2">定理1 比较判别法</h2><p>设<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x),g(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">(a,b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span>上连续，且<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>0</mn><mo>≤</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>≤</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">0\leq f(x)\leq g(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7804em;vertical-align:-0.136em;"></span><span class="mord">0</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>，则</p><ol><li>若<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>收敛，则<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>收敛</li><li>若<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>发散，则<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>发散</li></ol><h2 id="定理2-极限判别法-2">定理2 极限判别法</h2><p>设<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x),g(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">(a,b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span>上非负连续，且<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><mi>a</mi><mo>+</mo></mrow></msub><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mrow><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><mi>λ</mi></mrow><annotation encoding="application/x-tex">\lim_{x\to a+}\frac{f(x)}{g(x)}=\lambda</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.53em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.2583em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mathnormal mtight">a</span><span class="mord mtight">+</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2083em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.01em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">λ</span></span></span></span>，则</p><ol><li>当<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>λ</mi><mo>&gt;</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\lambda &gt; 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7335em;vertical-align:-0.0391em;"></span><span class="mord mathnormal">λ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>时，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>与<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>同敛散</li><li>当<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>λ</mi><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\lambda=0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">λ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>时，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>收敛，则<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>收敛</li><li>当<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>λ</mi><mo>=</mo><mo>+</mo><mi mathvariant="normal">∞</mi></mrow><annotation encoding="application/x-tex">\lambda=+\infty</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">λ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord">+</span><span class="mord">∞</span></span></span></span>时，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}g(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>发散，则<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int_{a}^{b}f(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.3998em;vertical-align:-0.3558em;"></span><span class="mop"><span class="mop op-symbol small-op" style="margin-right:0.19445em;position:relative;top:-0.0006em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.044em;"><span style="top:-2.3442em;margin-left:-0.1945em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.2579em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.3558em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span>发散</li></ol><h2 id="常用结论-2">常用结论</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msubsup><mo>∫</mo><mi>a</mi><mi>b</mi></msubsup><mfrac><mn>1</mn><mrow><mo stretchy="false">(</mo><mi>x</mi><mo>−</mo><mi>a</mi><msup><mo stretchy="false">)</mo><mi>p</mi></msup></mrow></mfrac><mi>d</mi><mi>x</mi><mrow><mo fence="true">{</mo><mtable rowspacing="0.36em" columnalign="left left" columnspacing="1em"><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mrow><mi>p</mi><mo>&lt;</mo><mn>1</mn><mo separator="true">,</mo></mrow></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mtext>收敛</mtext></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel="0" displaystyle="false"><mrow><mi>p</mi><mo>≥</mo><mn>1</mn><mo separator="true">,</mo></mrow></mstyle></mtd><mtd><mstyle scriptlevel="0" displaystyle="false"><mtext>发散</mtext></mstyle></mtd></mtr></mtable></mrow></mrow><annotation encoding="application/x-tex">\int_{a}^{b}\frac{1}{(x-a)^p}dx \begin{cases} p&lt;1, &amp; 收敛 \\ p\geq 1, &amp; 发散   \end{cases} </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:3em;vertical-align:-1.25em;"></span><span class="mop"><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.599em;"><span style="top:-1.7881em;margin-left:-0.4445em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.8129em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.9119em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal">a</span><span class="mclose"><span class="mclose">)</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.5904em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">p</span></span></span></span></span></span></span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.936em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="minner"><span class="mopen delimcenter" style="top:0em;"><span class="delimsizing size4">{</span></span><span class="mord"><span class="mtable"><span class="col-align-l"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.69em;"><span style="top:-3.69em;"><span class="pstrut" style="height:3.008em;"></span><span class="mord"><span class="mord mathnormal">p</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mord">1</span><span class="mpunct">,</span></span></span><span style="top:-2.25em;"><span class="pstrut" style="height:3.008em;"></span><span class="mord"><span class="mord mathnormal">p</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≥</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mord">1</span><span class="mpunct">,</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:1.19em;"><span></span></span></span></span></span><span class="arraycolsep" style="width:1em;"></span><span class="col-align-l"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.69em;"><span style="top:-3.69em;"><span class="pstrut" style="height:3.008em;"></span><span class="mord"><span class="mord cjk_fallback">收敛</span></span></span><span style="top:-2.25em;"><span class="pstrut" style="height:3.008em;"></span><span class="mord"><span class="mord cjk_fallback">发散</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:1.19em;"><span></span></span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p><h1>题型一 反常积分的敛散性</h1><h1>题型二 反常积分的计算</h1>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;一、无穷区间上的反常积分&lt;/h1&gt;
&lt;h2 id=&quot;定义1&quot;&gt;定义1&lt;/h2&gt;
&lt;p&gt;&lt;span class=&quot;katex-display&quot;&gt;&lt;span class=&quot;katex&quot;&gt;&lt;span class=&quot;katex-mathml&quot;&gt;&lt;math xmlns=&quot;http:</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>windows包管理器scoop的使用</title>
    <link href="http://example.com/post/d256eb21.html"/>
    <id>http://example.com/post/d256eb21.html</id>
    <published>2025-03-25T12:34:39.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>介绍</h1><p>Scoop是Windows上的包管理软件，类似Linux操作系统上的apt、yum。</p><h1>安装</h1><ol><li>首先确保您已允许 PowerShell 执行本地脚本：</li></ol><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser </span><br></pre></td></tr></table></figure><ol start="2"><li>简单安装<br>直接在powershell里运行</li></ol><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">irm get.scoop.sh | iex</span><br></pre></td></tr></table></figure><ol start="3"><li>指定路径安装</li></ol><p>首先下载安装脚本</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">irm get.scoop.sh -outfile &#x27;install.ps1&#x27;</span><br></pre></td></tr></table></figure><p>(可选)查看安装程序的所有可配置参数。</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">.\install.ps1 -?</span><br></pre></td></tr></table></figure><p>通常我们需要自定义安装目录,一般将目录放置在D盘中防止C盘爆满.需要新建两个文件夹,一个是用户安装目录,另一个是全局安装目录</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">.\install.ps1 -ScoopDir &#x27;D:\Applications\Scoop&#x27; -ScoopGlobalDir &#x27;F:\GlobalScoopApps&#x27; -NoProxy</span><br></pre></td></tr></table></figure><p>其中 -ScoopDir 后跟用户安装目录, -ScoopGlobalDir 后跟全局安装目录</p><p>或者，您可以使用传统方法通过设置环境变量来配置自定义目录。（不推荐）</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">$env:SCOOP=&#x27;D:\Applications\Scoop&#x27;</span><br><span class="line">$env:SCOOP_GLOBAL=&#x27;F:\GlobalScoopApps&#x27;</span><br><span class="line">[Environment]::SetEnvironmentVariable(&#x27;SCOOP_GLOBAL&#x27;, $env:SCOOP_GLOBAL, &#x27;Machine&#x27;)</span><br><span class="line">irm get.scoop.sh | iex</span><br></pre></td></tr></table></figure><h1>使用</h1><p>首次使用需要先安装git</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop isntall git</span><br></pre></td></tr></table></figure><p>scoop的软件目录都存放一个个库(bucket)中,软件安装时会默认安装main库,想要安装更多软件就需要先添加库,例如</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">scoop bucket add extras</span><br><span class="line"></span><br><span class="line">scoop update</span><br></pre></td></tr></table></figure><p>想要安装软件,可以先搜索可用的软件,使用</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop search 软件关键词</span><br></pre></td></tr></table></figure><p>然后安装软件</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop install 软件名</span><br></pre></td></tr></table></figure><p>或者指定库里的软件,例如</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop install extras/app</span><br></pre></td></tr></table></figure><p>还可以指定版本安装</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop install git@2.31.1</span><br></pre></td></tr></table></figure><h1>其他命令还有<br>&lt;&lt;&lt;&lt;&lt;&lt;&lt; HEAD</h1><p>更新软件</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop update</span><br></pre></td></tr></table></figure><blockquote><blockquote><blockquote><blockquote><blockquote><blockquote><blockquote><p>test<br>列出已安装的库</p></blockquote></blockquote></blockquote></blockquote></blockquote></blockquote></blockquote><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop list</span><br></pre></td></tr></table></figure><p>查看已订阅的库</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop bucket list</span><br></pre></td></tr></table></figure><p>删除已安装的软件</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">scoop uninstall 软件名</span><br></pre></td></tr></table></figure><p>如果在短时间内使用scoop search次数过多会触发github流控,此时可以登陆github-Setting-Developer Settings-Tokens(classic)-Generate new token<br>创建新的github token并复制在windows本地powrsehll中执行</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">scoop config gh_token 你的token</span><br><span class="line"></span><br></pre></td></tr></table></figure><h1>推荐的bucket</h1><h3 id="官方">官方</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">scoop bucket add extras</span><br><span class="line">scoop bucket add versions</span><br><span class="line"></span><br></pre></td></tr></table></figure><h3 id="第三方">第三方</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">scoop bucket add aki https://github.com/akirco/aki-apps.git</span><br><span class="line">scoop bucket add dorado https://github.com/chawyehsu/dorado.git</span><br><span class="line">scoop bucket add echo https://github.com/echoiron/echo-scoop.git</span><br><span class="line">scoop bucket add lemon https://github.com/hoilc/scoop-lemon.git</span><br><span class="line">scoop bucket add scoopet https://github.com/ivaquero/scoopet.git</span><br><span class="line">scoop bucket add tomato https://github.com/zhoujin7/tomato.git</span><br><span class="line">scoop bucket add scoop-zapps https://github.com/kkzzhizhou/scoop-zapps.git</span><br><span class="line">scoop update </span><br><span class="line"></span><br><span class="line"></span><br></pre></td></tr></table></figure><h1>参考</h1><p><a href="https://oudezhinu.com/archives/windows-scoop#%E6%9B%B4%E6%94%B9scoop%E6%9C%AC%E8%BA%AB%E4%BB%93%E5%BA%93"> 欧德的半位面</a></p><p><a href="https://github.com/ScoopInstaller/Install">官方github</a></p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;介绍&lt;/h1&gt;
&lt;p&gt;Scoop是Windows上的包管理软件，类似Linux操作系统上的apt、yum。&lt;/p&gt;
&lt;h1&gt;安装&lt;/h1&gt;
&lt;ol&gt;
&lt;li&gt;首先确保您已允许 PowerShell 执行本地脚本：&lt;/li&gt;
&lt;/ol&gt;
&lt;figure class=&quot;hig</summary>
      
    
    
    
    
    <category term="技术" scheme="http://example.com/tags/%E6%8A%80%E6%9C%AF/"/>
    
  </entry>
  
  <entry>
    <title>不定积分</title>
    <link href="http://example.com/post/c6cdbc15.html"/>
    <id>http://example.com/post/c6cdbc15.html</id>
    <published>2025-03-11T12:44:42.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h2 id="第一类换元积分法">第一类换元积分法</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo>∫</mo><mi>f</mi><mo stretchy="false">[</mo><mi>φ</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><msup><mi>φ</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><mo>∫</mo><mi>f</mi><mo stretchy="false">[</mo><mi>φ</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><mi>d</mi><mi>φ</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mi>F</mi><mo stretchy="false">[</mo><mi>φ</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><mo>+</mo><mi>C</mi></mrow><annotation encoding="application/x-tex">\int f[φ(x)]φ&#x27;(x)dx = \int f[φ(x)]dφ(x) = F[φ(x)] + C</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.2222em;vertical-align:-0.8622em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">[</span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)]</span><span class="mord"><span class="mord mathnormal">φ</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.2222em;vertical-align:-0.8622em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">[</span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)]</span><span class="mord mathnormal">d</span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">[</span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)]</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07153em;">C</span></span></span></span></span></p><h2 id="第二类换元积分法">第二类换元积分法</h2><p>如果<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>x</mi><mo>=</mo><mi>φ</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">x = φ(t)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span></span></span></span>是单调可导函数，且<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>φ</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo><mo mathvariant="normal">≠</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">φ&#x27;(t) \neq 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal">φ</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel"><span class="mrel"><span class="mord vbox"><span class="thinbox"><span class="rlap"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="inner"><span class="mord"><span class="mrel"></span></span></span><span class="fix"></span></span></span></span></span><span class="mrel">=</span></span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，则有</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo>∫</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><mo>∫</mo><mi>f</mi><mo stretchy="false">[</mo><mi>φ</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><msup><mi>φ</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo><mi>d</mi><mi>t</mi></mrow><annotation encoding="application/x-tex">\int f(x)dx = \int f[φ(t)]φ&#x27;(t)dt </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.2222em;vertical-align:-0.8622em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.2222em;vertical-align:-0.8622em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">[</span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)]</span><span class="mord"><span class="mord mathnormal">φ</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">t</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">t</span></span></span></span></span></p><h2 id="分部积分法">分部积分法</h2><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo>∫</mo><mi>u</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><msup><mi>v</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi><mo>=</mo><mi>u</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>v</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>−</mo><mo>∫</mo><msup><mi>u</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>v</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mi>d</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">\int u(x)v&#x27;(x)dx = u(x)v(x) - \int u&#x27;(x)v(x)dx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.2222em;vertical-align:-0.8622em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">u</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">u</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.2222em;vertical-align:-0.8622em;"></span><span class="mop op-symbol large-op" style="margin-right:0.44445em;position:relative;top:-0.0011em;">∫</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal">u</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord mathnormal">d</span><span class="mord mathnormal">x</span></span></span></span></span></p>]]></content>
    
    
      
      
    <summary type="html">&lt;h2 id=&quot;第一类换元积分法&quot;&gt;第一类换元积分法&lt;/h2&gt;
&lt;p&gt;&lt;span class=&quot;katex-display&quot;&gt;&lt;span class=&quot;katex&quot;&gt;&lt;span class=&quot;katex-mathml&quot;&gt;&lt;math xmlns=&quot;http://www.w3.org</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>高数常用结论(更新中)</title>
    <link href="http://example.com/post/8002b166.html"/>
    <id>http://example.com/post/8002b166.html</id>
    <published>2025-03-05T08:21:44.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>极限</h1><ul><li>当$X \to 0 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mtext>时，</mtext></mrow><annotation encoding="application/x-tex">时，</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord cjk_fallback">时，</span></span></span></span>(1+X)^\alpha -1 \sim \alpha X$</li><li>当<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>X</mi><mo>→</mo><mn>1</mn></mrow><annotation encoding="application/x-tex">X \to 1</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07847em;">X</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">→</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">1</span></span></span></span>时, <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>X</mi><mi>α</mi></msup><mo>∼</mo><mi>α</mi><mo stretchy="false">(</mo><mi>X</mi><mo>−</mo><mn>1</mn><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">X^\alpha \sim \alpha(X-1)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.07847em;">X</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6644em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.0037em;">α</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.0037em;">α</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.07847em;">X</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">1</span><span class="mclose">)</span></span></span></span></li></ul><h1>等价无穷小</h1><ul><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mi>x</mi><mo>∼</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">\sin x \sim x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6679em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mn>1</mn><mo>−</mo><mi>cos</mi><mo>⁡</mo><mi>x</mi><mo>∼</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><msup><mi>x</mi><mn>2</mn></msup></mrow><annotation encoding="application/x-tex">1-\cos x \sim \frac{1}{2}x^2</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7278em;vertical-align:-0.0833em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mn>1</mn><mo>−</mo><msup><mrow><mi>cos</mi><mo>⁡</mo></mrow><mi>a</mi></msup><mi>x</mi><mo>∼</mo><mfrac><mi>a</mi><mn>2</mn></mfrac><msup><mi>x</mi><mn>2</mn></msup></mrow><annotation encoding="application/x-tex">1-\cos^a x \sim \frac{a}{2}x^2</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7278em;vertical-align:-0.0833em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.7144em;"></span><span class="mop"><span class="mop">cos</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.7936em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.1076em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">a</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>tan</mi><mo>⁡</mo><mi>x</mi><mo>∼</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">\tan x \sim x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6151em;"></span><span class="mop">tan</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>arctan</mi><mo>⁡</mo><mi>x</mi><mo>∼</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">\arctan x \sim x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6151em;"></span><span class="mop">arctan</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>e</mi><mi>x</mi></msup><mo>−</mo><mn>1</mn><mo>∼</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">e^x -1 \sim x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7977em;vertical-align:-0.0833em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>ln</mi><mo>⁡</mo><mo stretchy="false">(</mo><mn>1</mn><mo>+</mo><mi>x</mi><mo stretchy="false">)</mo><mo>∼</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">\ln (1+x) \sim x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">ln</span><span class="mopen">(</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mo stretchy="false">(</mo><mn>1</mn><mo>+</mo><mi>x</mi><msup><mo stretchy="false">)</mo><mi>α</mi></msup><mo>−</mo><mn>1</mn><mo>∼</mo><mi>α</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">(1+x)^\alpha -1 \sim \alpha x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">x</span><span class="mclose"><span class="mclose">)</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.0037em;">α</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">αx</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><munder><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>A</mi><mo>→</mo><mn>1</mn></mrow></munder><mi>ln</mi><mo>⁡</mo><mi>A</mi><mo>∼</mo><mi>A</mi><mo>−</mo><mn>1</mn></mrow><annotation encoding="application/x-tex">\lim_{A \to 1} \ln A \sim A-1</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.4388em;vertical-align:-0.7443em;"></span><span class="mop op-limits"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6944em;"><span style="top:-2.3557em;margin-left:0em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">A</span><span class="mrel mtight">→</span><span class="mord mtight">1</span></span></span></span><span style="top:-3em;"><span class="pstrut" style="height:3em;"></span><span><span class="mop">lim</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.7443em;"><span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">ln</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∼</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">1</span></span></span></span></span></p></li></ul><h1>三角函数</h1><h3 id="两角和差公式">两角和差公式</h3><ul><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>+</mo><mi>B</mi><mo stretchy="false">)</mo><mo>=</mo><mi>sin</mi><mo>⁡</mo><mi>A</mi><mi>cos</mi><mo>⁡</mo><mi>B</mi><mo>+</mo><mi>cos</mi><mo>⁡</mo><mi>A</mi><mi>sin</mi><mo>⁡</mo><mi>B</mi></mrow><annotation encoding="application/x-tex">\sin(A+B) = \sin A\cos B + \cos A\sin B</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">sin</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>−</mo><mi>B</mi><mo stretchy="false">)</mo><mo>=</mo><mi>sin</mi><mo>⁡</mo><mi>A</mi><mi>cos</mi><mo>⁡</mo><mi>B</mi><mo>−</mo><mi>cos</mi><mo>⁡</mo><mi>A</mi><mi>sin</mi><mo>⁡</mo><mi>B</mi></mrow><annotation encoding="application/x-tex">\sin(A-B) = \sin A\cos B - \cos A\sin B</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">sin</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>cos</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>+</mo><mi>B</mi><mo stretchy="false">)</mo><mo>=</mo><mi>cos</mi><mo>⁡</mo><mi>A</mi><mi>cos</mi><mo>⁡</mo><mi>B</mi><mo>−</mo><mi>sin</mi><mo>⁡</mo><mi>A</mi><mi>sin</mi><mo>⁡</mo><mi>B</mi></mrow><annotation encoding="application/x-tex">\cos(A+B) = \cos A\cos B - \sin A\sin B</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">cos</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>cos</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>−</mo><mi>B</mi><mo stretchy="false">)</mo><mo>=</mo><mi>cos</mi><mo>⁡</mo><mi>A</mi><mi>cos</mi><mo>⁡</mo><mi>B</mi><mo>+</mo><mi>sin</mi><mo>⁡</mo><mi>A</mi><mi>sin</mi><mo>⁡</mo><mi>B</mi></mrow><annotation encoding="application/x-tex">\cos(A-B) = \cos A\cos B + \sin A\sin B</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">cos</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span></span></p></li></ul><p><strong>通过两角和差可推出积化和差和和差化积</strong></p><h3 id="积化和差公式">积化和差公式</h3><ul><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mi>A</mi><mi>cos</mi><mo>⁡</mo><mi>B</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mo stretchy="false">[</mo><mi>sin</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>+</mo><mi>B</mi><mo stretchy="false">)</mo><mo>+</mo><mi>sin</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>−</mo><mi>B</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">\sin A\cos B = \frac{1}{2}[\sin(A+B) + \sin(A-B)]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mopen">[</span><span class="mop">sin</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">sin</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)]</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>cos</mi><mo>⁡</mo><mi>A</mi><mi>sin</mi><mo>⁡</mo><mi>B</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mo stretchy="false">[</mo><mi>sin</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>+</mo><mi>B</mi><mo stretchy="false">)</mo><mo>−</mo><mi>sin</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>−</mo><mi>B</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">\cos A\sin B = \frac{1}{2}[\sin(A+B) - \sin(A-B)]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mopen">[</span><span class="mop">sin</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">sin</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)]</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>cos</mi><mo>⁡</mo><mi>A</mi><mi>cos</mi><mo>⁡</mo><mi>B</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mo stretchy="false">[</mo><mi>cos</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>+</mo><mi>B</mi><mo stretchy="false">)</mo><mo>+</mo><mi>cos</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>−</mo><mi>B</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">\cos A\cos B = \frac{1}{2}[\cos(A+B) + \cos(A-B)]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mopen">[</span><span class="mop">cos</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">cos</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)]</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mi>A</mi><mi>sin</mi><mo>⁡</mo><mi>B</mi><mo>=</mo><mo>−</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mo stretchy="false">[</mo><mi>cos</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>+</mo><mi>B</mi><mo stretchy="false">)</mo><mo>−</mo><mi>cos</mi><mo>⁡</mo><mo stretchy="false">(</mo><mi>A</mi><mo>−</mo><mi>B</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">\sin A\sin B = -\frac{1}{2}[\cos(A+B) - \cos(A-B)]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord">−</span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mopen">[</span><span class="mop">cos</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">cos</span><span class="mopen">(</span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mclose">)]</span></span></span></span></span></p></li></ul><h3 id="和差化积公式">和差化积公式</h3><ul><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mi>A</mi><mo>+</mo><mi>sin</mi><mo>⁡</mo><mi>B</mi><mo>=</mo><mn>2</mn><mi>sin</mi><mo>⁡</mo><mfrac><mrow><mi>A</mi><mo>+</mo><mi>B</mi></mrow><mn>2</mn></mfrac><mi>cos</mi><mo>⁡</mo><mfrac><mrow><mi>A</mi><mo>−</mo><mi>B</mi></mrow><mn>2</mn></mfrac></mrow><annotation encoding="application/x-tex">\sin A + \sin B = 2\sin\frac{A+B}{2}\cos\frac{A-B}{2}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0463em;vertical-align:-0.686em;"></span><span class="mord">2</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3603em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3603em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mi>A</mi><mo>−</mo><mi>sin</mi><mo>⁡</mo><mi>B</mi><mo>=</mo><mn>2</mn><mi>cos</mi><mo>⁡</mo><mfrac><mrow><mi>A</mi><mo>+</mo><mi>B</mi></mrow><mn>2</mn></mfrac><mi>sin</mi><mo>⁡</mo><mfrac><mrow><mi>A</mi><mo>−</mo><mi>B</mi></mrow><mn>2</mn></mfrac></mrow><annotation encoding="application/x-tex">\sin A - \sin B = 2\cos\frac{A+B}{2}\sin\frac{A-B}{2}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0463em;vertical-align:-0.686em;"></span><span class="mord">2</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3603em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3603em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>cos</mi><mo>⁡</mo><mi>A</mi><mo>+</mo><mi>cos</mi><mo>⁡</mo><mi>B</mi><mo>=</mo><mn>2</mn><mi>cos</mi><mo>⁡</mo><mfrac><mrow><mi>A</mi><mo>+</mo><mi>B</mi></mrow><mn>2</mn></mfrac><mi>cos</mi><mo>⁡</mo><mfrac><mrow><mi>A</mi><mo>−</mo><mi>B</mi></mrow><mn>2</mn></mfrac></mrow><annotation encoding="application/x-tex">\cos A + \cos B = 2\cos\frac{A+B}{2}\cos\frac{A-B}{2}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0463em;vertical-align:-0.686em;"></span><span class="mord">2</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3603em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3603em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>cos</mi><mo>⁡</mo><mi>A</mi><mo>−</mo><mi>cos</mi><mo>⁡</mo><mi>B</mi><mo>=</mo><mo>−</mo><mn>2</mn><mi>sin</mi><mo>⁡</mo><mfrac><mrow><mi>A</mi><mo>+</mo><mi>B</mi></mrow><mn>2</mn></mfrac><mi>sin</mi><mo>⁡</mo><mfrac><mrow><mi>A</mi><mo>−</mo><mi>B</mi></mrow><mn>2</mn></mfrac></mrow><annotation encoding="application/x-tex">\cos A - \cos B = -2\sin\frac{A+B}{2}\sin\frac{A-B}{2}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7667em;vertical-align:-0.0833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.0463em;vertical-align:-0.686em;"></span><span class="mord">−</span><span class="mord">2</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3603em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3603em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">A</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p></li></ul><h1>泰勒展开</h1><ul><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mi>x</mi><mo>=</mo><mi>x</mi><mo>−</mo><mfrac><mn>1</mn><mrow><mn>3</mn><mo stretchy="false">!</mo></mrow></mfrac><msup><mi>x</mi><mn>3</mn></msup><mo>+</mo><mfrac><mn>1</mn><mrow><mn>5</mn><mo stretchy="false">!</mo></mrow></mfrac><msup><mi>x</mi><mn>5</mn></msup><mo>−</mo><mfrac><mn>1</mn><mrow><mn>7</mn><mo stretchy="false">!</mo></mrow></mfrac><mo>+</mo><mi>o</mi><mo stretchy="false">(</mo><msup><mi>x</mi><mn>7</mn></msup><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\sin x = x - \frac{1}{3!}x^3+ \frac{1}{5!}x^5 - \frac{1}{7!} + o(x^7)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6679em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">3</span><span class="mclose">!</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">3</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">5</span><span class="mclose">!</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">5</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">7</span><span class="mclose">!</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.1141em;vertical-align:-0.25em;"></span><span class="mord mathnormal">o</span><span class="mopen">(</span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">7</span></span></span></span></span></span></span></span><span class="mclose">)</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>cos</mi><mo>⁡</mo><mi>x</mi><mo>=</mo><mn>1</mn><mo>−</mo><mfrac><mn>1</mn><mrow><mn>2</mn><mo stretchy="false">!</mo></mrow></mfrac><msup><mi>x</mi><mn>2</mn></msup><mo>+</mo><mfrac><mn>1</mn><mrow><mn>4</mn><mo stretchy="false">!</mo></mrow></mfrac><msup><mi>x</mi><mn>4</mn></msup><mo>−</mo><mfrac><mn>1</mn><mrow><mn>6</mn><mo stretchy="false">!</mo></mrow></mfrac><msup><mi>x</mi><mn>6</mn></msup><mo>+</mo><mi>o</mi><mo stretchy="false">(</mo><msup><mi>x</mi><mn>6</mn></msup><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\cos x = 1-\frac{1}{2!}x^2+\frac{1}{4!}x^4-\frac{1}{6!}x^6+o(x^6)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7278em;vertical-align:-0.0833em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span><span class="mclose">!</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">4</span><span class="mclose">!</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">4</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">6</span><span class="mclose">!</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">6</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.1141em;vertical-align:-0.25em;"></span><span class="mord mathnormal">o</span><span class="mopen">(</span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">6</span></span></span></span></span></span></span></span><span class="mclose">)</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>tan</mi><mo>⁡</mo><mi>x</mi><mo>=</mo><mi>x</mi><mo>+</mo><mfrac><mn>1</mn><mn>3</mn></mfrac><msup><mi>x</mi><mn>3</mn></msup><mo>+</mo><mfrac><mn>2</mn><mn>15</mn></mfrac><msup><mi>x</mi><mn>5</mn></msup><mo>+</mo><mi>o</mi><mo stretchy="false">(</mo><msup><mi>x</mi><mn>5</mn></msup><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\tan x = x+\frac{1}{3}x^3+\frac{2}{15}x^5+o(x^5)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6151em;"></span><span class="mop">tan</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">3</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">3</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">15</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">5</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.1141em;vertical-align:-0.25em;"></span><span class="mord mathnormal">o</span><span class="mopen">(</span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">5</span></span></span></span></span></span></span></span><span class="mclose">)</span></span></span></span></span></p></li><li><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>e</mi><mi>x</mi></msup><mo>=</mo><mn>1</mn><mo>+</mo><mi>x</mi><mo>+</mo><mfrac><mn>1</mn><mrow><mn>2</mn><mo stretchy="false">!</mo></mrow></mfrac><msup><mi>x</mi><mn>2</mn></msup><mo>+</mo><mfrac><mn>1</mn><mrow><mi>n</mi><mo stretchy="false">!</mo></mrow></mfrac><msup><mi>x</mi><mi>n</mi></msup><mo>+</mo><mi>o</mi><mo stretchy="false">(</mo><msup><mi>x</mi><mi>n</mi></msup><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">e^x = 1+x+\frac{1}{2!}x^2+\frac{1}{n!}x^n+o(x^n)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7144em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7278em;vertical-align:-0.0833em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6667em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span><span class="mclose">!</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:2.0074em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.3214em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">n</span><span class="mclose">!</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">o</span><span class="mopen">(</span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7144em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span></span></span></span></span></span><span class="mclose">)</span></span></span></span></span></p></li></ul>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;极限&lt;/h1&gt;
&lt;ul&gt;
&lt;li&gt;当$X &#92;to 0 &lt;span class=&quot;katex&quot;&gt;&lt;span class=&quot;katex-mathml&quot;&gt;&lt;math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot;&gt;&lt;semantics&gt;&lt;m</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>微分中值定理</title>
    <link href="http://example.com/post/58a6fadb.html"/>
    <id>http://example.com/post/58a6fadb.html</id>
    <published>2025-03-05T02:33:35.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>微分中值定理与导数的应用</h1><h2 id="罗尔定理">罗尔定理</h2><p>定义：设函数<br>(1) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在闭区间 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">[a, b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span> 上连续，<br>(2) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在开区间 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">(a, b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span> 内可导，<br>(3) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(a) = f(b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>，<br>则∃ξ ∈ (a, b), 使得 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">f&#x27;(ξ) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span><br><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/20250305104622974.png" alt=""></p><details><summary>证明</summary><p>由于 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在闭区间 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">[a, b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span> 上连续，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在闭区间 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">[a, b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span> 上必取得最大值和最小值，记为 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>M</mi></mrow><annotation encoding="application/x-tex">M</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.10903em;">M</span></span></span></span> 和 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>m</mi></mrow><annotation encoding="application/x-tex">m</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">m</span></span></span></span>，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>M</mi><mo>≥</mo><mi>m</mi></mrow><annotation encoding="application/x-tex">M \geq m</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8193em;vertical-align:-0.136em;"></span><span class="mord mathnormal" style="margin-right:0.10903em;">M</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≥</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">m</span></span></span></span>。</p><p>(1) 若 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>M</mi><mo>=</mo><mi>m</mi></mrow><annotation encoding="application/x-tex">M = m</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.10903em;">M</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">m</span></span></span></span>，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在闭区间 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">[a, b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span> 上为常数，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">f&#x27;(x) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi mathvariant="normal">∀</mi><mi>x</mi><mo>∈</mo><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\forall x \in (a, b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7335em;vertical-align:-0.0391em;"></span><span class="mord">∀</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">f&#x27;(x) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>。</p><p>(2) 若 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>M</mi><mo>&gt;</mo><mi>m</mi></mrow><annotation encoding="application/x-tex">M &gt; m</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7224em;vertical-align:-0.0391em;"></span><span class="mord mathnormal" style="margin-right:0.10903em;">M</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">m</span></span></span></span>，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>M</mi></mrow><annotation encoding="application/x-tex">M</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.10903em;">M</span></span></span></span> 和 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>m</mi></mrow><annotation encoding="application/x-tex">m</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">m</span></span></span></span> 中至少有一个在 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">(a, b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span> 内取得，不妨设 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ξ</mi><mo>∈</mo><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\xi \in (a, b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>，使得 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>=</mo><mi>M</mi></mrow><annotation encoding="application/x-tex">f(\xi) = M</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.10903em;">M</span></span></span></span>，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ξ</mi></mrow><annotation encoding="application/x-tex">\xi</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span></span></span></span> 为 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 的极大值点，则 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">f&#x27;(\xi) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>。</p></details><h2 id="拉格朗日中值定理">拉格朗日中值定理</h2><p><strong>定义</strong>：设函数<br>(1) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">[a, b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span> 上连续，<br>(2) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">(a, b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span> 内可导，<br>则至少存在一个 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ξ</mi><mo>∈</mo><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\xi \in (a, b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>，使得</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>=</mo><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>−</mo><mi>f</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo></mrow><mrow><mi>b</mi><mo>−</mo><mi>a</mi></mrow></mfrac></mrow><annotation encoding="application/x-tex">f&#x27;(ξ) = \frac{f(b) - f(a)}{b - a}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0519em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8019em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.1963em;vertical-align:-0.7693em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.427em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal">b</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal">a</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.7693em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/20250305104722349.png" alt=""><br><strong>注</strong>：1) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>a</mi><mo>&gt;</mo><mi>b</mi><mo separator="true">,</mo><mi>a</mi><mo>&lt;</mo><mi>b</mi></mrow><annotation encoding="application/x-tex">a&gt;b, a&lt;b</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.5782em;vertical-align:-0.0391em;"></span><span class="mord mathnormal">a</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">b</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">a</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">b</span></span></span></span> 结论都成立<br>2) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>−</mo><mi>b</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo><mo>=</mo><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mi>b</mi><mo>−</mo><mi>a</mi><mo stretchy="false">)</mo><mo>=</mo><mi>f</mi><mi mathvariant="normal">‘</mi><mo stretchy="false">[</mo><mi>a</mi><mo>+</mo><mi>θ</mi><mo stretchy="false">(</mo><mi>b</mi><mo>−</mo><mi>a</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><mo stretchy="false">(</mo><mi>b</mi><mo>−</mo><mi>a</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(b)-b(a) = f&#x27;(ξ)(b-a) = f`[a+θ(b-a)](b-a)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">b</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord">‘</span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">a</span><span class="mclose">)]</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">a</span><span class="mclose">)</span></span></span></span><br>有限增量公式：<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><msub><mi>x</mi><mn>0</mn></msub><mo>+</mo><mi mathvariant="normal">Δ</mi><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><msub><mi>x</mi><mn>0</mn></msub><mo>+</mo><mi>θ</mi><mi mathvariant="normal">Δ</mi><mi>x</mi><mo stretchy="false">)</mo><mi mathvariant="normal">Δ</mi><mi>x</mi></mrow><annotation encoding="application/x-tex">f(x_0+Δx) = f&#x27;(x_0+θΔx)Δx</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">Δ</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.02778em;">θ</span><span class="mord">Δ</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mord">Δ</span><span class="mord mathnormal">x</span></span></span></span></p><p><strong>推论</strong>：设 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>I</mi></mrow><annotation encoding="application/x-tex">I</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07847em;">I</span></span></span></span> 内可导，则在 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>I</mi></mrow><annotation encoding="application/x-tex">I</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal" style="margin-right:0.07847em;">I</span></span></span></span> 上<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 为常数 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo>⇔</mo></mrow><annotation encoding="application/x-tex">\Leftrightarrow</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.3669em;"></span><span class="mrel">⇔</span></span></span></span> <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">f&#x27;(x) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span></p><details><summary>证明</summary><p>令<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>−</mo><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>−</mo><mi>f</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo></mrow><mrow><mi>b</mi><mo>−</mo><mi>a</mi></mrow></mfrac><mi>x</mi></mrow><annotation encoding="application/x-tex">F(x) = f(x) - \frac{f(b)-f(a)}{b-a}x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.4133em;vertical-align:-0.4033em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.01em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">b</span><span class="mclose mtight">)</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">a</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4033em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord mathnormal">x</span></span></span></span> ，则<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">F(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">[a,b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span>上连续，在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">(a,b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>内可导，可证<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo><mo>=</mo><mi>F</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">F(a) = F(b) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，则由罗尔定理，存在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ξ</mi><mo>∈</mo><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\xi \in (a,b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>，使得<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>F</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">F&#x27;(\xi) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，即<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>=</mo><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>−</mo><mi>f</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo></mrow><mrow><mi>b</mi><mo>−</mo><mi>a</mi></mrow></mfrac></mrow><annotation encoding="application/x-tex">f&#x27;(\xi) = \frac{f(b)-f(a)}{b-a}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.4133em;vertical-align:-0.4033em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.01em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">b</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight">a</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">b</span><span class="mclose mtight">)</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">a</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4033em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></p></details><details><summary>例1 试证 <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>|</mo><mi>sin</mi><mi>x</mi><mo>-</mo><mi>sin</mi><mi>y</mi><mo>|</mo><mo>≤</mo><mo>|</mo><mi>x</mi><mo>-</mo><mi>y</mi><mo>|</mo></mrow></math></summary><p>[证] 由拉格朗日中值定理，存在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ξ</mi></mrow><annotation encoding="application/x-tex">\xi</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span></span></span></span>在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>x</mi></mrow><annotation encoding="application/x-tex">x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span></span></span></span>与<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>y</mi></mrow><annotation encoding="application/x-tex">y</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.625em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span></span></span></span>之间，使得</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mi>x</mi><mo>−</mo><mi>sin</mi><mo>⁡</mo><mi>y</mi><mo>=</mo><mi>cos</mi><mo>⁡</mo><mi>ξ</mi><mo>⋅</mo><mo stretchy="false">(</mo><mi>x</mi><mo>−</mo><mi>y</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\sin x - \sin y = \cos \xi \cdot (x - y)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7512em;vertical-align:-0.0833em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.8623em;vertical-align:-0.1944em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">⋅</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mclose">)</span></span></span></span></span></p><p>两边取绝对值：</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi mathvariant="normal">∣</mi><mi>sin</mi><mo>⁡</mo><mi>x</mi><mo>−</mo><mi>sin</mi><mo>⁡</mo><mi>y</mi><mi mathvariant="normal">∣</mi><mo>=</mo><mi mathvariant="normal">∣</mi><mi>cos</mi><mo>⁡</mo><mi>ξ</mi><mi mathvariant="normal">∣</mi><mo>⋅</mo><mi mathvariant="normal">∣</mi><mi>x</mi><mo>−</mo><mi>y</mi><mi mathvariant="normal">∣</mi><mo>≤</mo><mn>1</mn><mo>⋅</mo><mi mathvariant="normal">∣</mi><mi>x</mi><mo>−</mo><mi>y</mi><mi mathvariant="normal">∣</mi></mrow><annotation encoding="application/x-tex">|\sin x - \sin y| = |\cos \xi| \cdot |x - y| \leq 1 \cdot |x - y|</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">∣</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mord">∣</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">∣</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">cos</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mord">∣</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">⋅</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">∣</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mord">∣</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">⋅</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">∣</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mord">∣</span></span></span></span></span></p><p>故得证<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi mathvariant="normal">∣</mi><mi>sin</mi><mo>⁡</mo><mi>x</mi><mo>−</mo><mi>sin</mi><mo>⁡</mo><mi>y</mi><mi mathvariant="normal">∣</mi><mo>≤</mo><mi mathvariant="normal">∣</mi><mi>x</mi><mo>−</mo><mi>y</mi><mi mathvariant="normal">∣</mi></mrow><annotation encoding="application/x-tex">|\sin x - \sin y| \leq |x - y|</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">∣</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mord">∣</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">≤</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">∣</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">y</span><span class="mord">∣</span></span></span></span></p></details><details><summary>例2 证明：当 <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>x</mi><mo>></mo><mn>0</mn></mrow></math> 时，<math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mi>x</mi><mrow><mn>1</mn><mo>+</mo><mi>x</mi></mrow></mfrac><mo><</mo><mi>ln</mi><mo>(</mo><mn>1</mn><mo>+</mo><mi>x</mi><mo>)</mo><mo><</mo><mi>x</mi></math></summary><p>[证] 根据拉格朗日中值定理，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ln</mi><mo>⁡</mo><mo stretchy="false">(</mo><mn>1</mn><mo>+</mo><mi>x</mi><mo stretchy="false">)</mo><mo>−</mo><mi>ln</mi><mo>⁡</mo><mn>1</mn><mo>=</mo><mfrac><mrow><mn>1</mn><mo>+</mo><mi>x</mi><mo>−</mo><mn>1</mn></mrow><mrow><mn>1</mn><mo>+</mo><mi>ξ</mi></mrow></mfrac><mo>=</mo><mfrac><mi>x</mi><mrow><mn>1</mn><mo>+</mo><mi>ξ</mi></mrow></mfrac></mrow><annotation encoding="application/x-tex">\ln(1+x)-\ln 1 =\frac{1+x-1}{1+ξ}=\frac{x}{1+ξ}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">ln</span><span class="mopen">(</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mop">ln</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.3262em;vertical-align:-0.4811em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8451em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">+</span><span class="mord mathnormal mtight" style="margin-right:0.04601em;">ξ</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">+</span><span class="mord mathnormal mtight">x</span><span class="mbin mtight">−</span><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4811em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.1765em;vertical-align:-0.4811em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6954em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">+</span><span class="mord mathnormal mtight" style="margin-right:0.04601em;">ξ</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4811em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span><br>其中，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>1</mn><mo>+</mo><mi>x</mi><mo>&gt;</mo><mi>ξ</mi><mo>&gt;</mo><mn>1</mn></mrow><annotation encoding="application/x-tex">1+x &gt; \xi &gt; 1</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7278em;vertical-align:-0.0833em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.5782em;vertical-align:-0.0391em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&gt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">1</span></span></span></span>，所以<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mfrac><mi>x</mi><mrow><mn>1</mn><mo>+</mo><mi>x</mi></mrow></mfrac><mo>&lt;</mo><mfrac><mi>x</mi><mrow><mn>1</mn><mo>+</mo><mi>ξ</mi></mrow></mfrac><mo>&lt;</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">\frac{x}{1+x} &lt; \frac{x}{1+ξ} &lt; x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0987em;vertical-align:-0.4033em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6954em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">+</span><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4033em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.1765em;vertical-align:-0.4811em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6954em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">+</span><span class="mord mathnormal mtight" style="margin-right:0.04601em;">ξ</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4811em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span></span></span></span><br>即<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mfrac><mi>x</mi><mrow><mn>1</mn><mo>+</mo><mi>x</mi></mrow></mfrac><mo>&lt;</mo><mi>ln</mi><mo>⁡</mo><mo stretchy="false">(</mo><mn>1</mn><mo>+</mo><mi>x</mi><mo stretchy="false">)</mo><mo>&lt;</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">\frac{x}{1+x} &lt; \ln(1+x) &lt; x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0987em;vertical-align:-0.4033em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6954em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">+</span><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4033em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mop">ln</span><span class="mopen">(</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">x</span></span></span></span></p></details><details><summary>例3 证明：当 <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>x</mi><mo>∈</mo><mo>(</mo><mn>0</mn><mo>,</mo><mfrac><mi>π</mi><mn>2</mn></mfrac><mo>)</mo></mrow></math> 时，<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>arctan</mi><mi>x</mi><mo>+</mo><mi>arctan</mi><mfrac><mn>1</mn><mi>x</mi></mfrac><mo>=</mo><mfrac><mi>π</mi><mn>2</mn></mfrac></mrow></math></summary><p>[证] 函数恒等于常数，则导数恒为0<br>令<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mi>a</mi><mi>r</mi><mi>c</mi><mi>t</mi><mi>a</mi><mi>n</mi><mi>x</mi><mo>+</mo><mi>a</mi><mi>r</mi><mi>c</mi><mi>t</mi><mi>a</mi><mi>n</mi><mfrac><mn>1</mn><mi>x</mi></mfrac></mrow><annotation encoding="application/x-tex">f(x) = arctan x + arctan \frac{1}{x}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6984em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">a</span><span class="mord mathnormal">rc</span><span class="mord mathnormal">t</span><span class="mord mathnormal">an</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.1901em;vertical-align:-0.345em;"></span><span class="mord mathnormal">a</span><span class="mord mathnormal">rc</span><span class="mord mathnormal">t</span><span class="mord mathnormal">an</span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8451em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span>，则<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mfrac><mn>1</mn><mrow><mn>1</mn><mo>+</mo><msup><mi>x</mi><mn>2</mn></msup></mrow></mfrac><mo>−</mo><mfrac><mn>1</mn><mrow><mn>1</mn><mo>+</mo><mfrac><mn>1</mn><msup><mi>x</mi><mn>2</mn></msup></mfrac></mrow></mfrac><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">f&#x27;(x) = \frac{1}{1+x^2} - \frac{1}{1+\frac{1}{x^2}} = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.2484em;vertical-align:-0.4033em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8451em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">+</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7463em;"><span style="top:-2.786em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4033em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.5918em;vertical-align:-0.7467em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8451em;"><span style="top:-2.599em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span><span class="mbin mtight">+</span><span class="mord mtight"><span class="mopen nulldelimiter sizing reset-size3 size6"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.8443em;"><span style="top:-2.5062em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.9384em;"><span style="top:-2.9384em;margin-right:0.1em;"><span class="pstrut" style="height:2.6444em;"></span><span class="mord mtight">2</span></span></span></span></span></span></span></span></span></span><span style="top:-3.2255em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line mtight" style="border-bottom-width:0.049em;"></span></span><span style="top:-3.384em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.4938em;"><span></span></span></span></span></span><span class="mclose nulldelimiter sizing reset-size3 size6"></span></span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">1</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.7467em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，<br>又<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo><mo>=</mo><mi>a</mi><mi>r</mi><mi>c</mi><mi>t</mi><mi>a</mi><mi>n</mi><mn>1</mn><mo>+</mo><mi>a</mi><mi>r</mi><mi>c</mi><mi>t</mi><mi>a</mi><mi>n</mi><mn>1</mn><mo>=</mo><mfrac><mi>π</mi><mn>2</mn></mfrac></mrow><annotation encoding="application/x-tex">f(1) = arctan 1 + arctan 1 = \frac{\pi}{2}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord">1</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7278em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">a</span><span class="mord mathnormal">rc</span><span class="mord mathnormal">t</span><span class="mord mathnormal">an</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord mathnormal">a</span><span class="mord mathnormal">rc</span><span class="mord mathnormal">t</span><span class="mord mathnormal">an</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0404em;vertical-align:-0.345em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6954em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">2</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">π</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span><br>所以<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mn>0</mn><mo separator="true">,</mo><mi>π</mi><mi mathvariant="normal">/</mi><mn>2</mn><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">(0,\pi /2)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord">0</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">π</span><span class="mord">/2</span><span class="mclose">)</span></span></span></span>内为常数，即<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mi>f</mi><mo stretchy="false">(</mo><mn>0</mn><mo stretchy="false">)</mo><mo>=</mo><mfrac><mi>π</mi><mn>2</mn></mfrac></mrow><annotation encoding="application/x-tex">f(x) = f(0) = \frac{\pi}{2}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord">0</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0404em;vertical-align:-0.345em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.6954em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">2</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.394em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">π</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.345em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></p></details><p><strong>常用不等式</strong>：<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>sin</mi><mo>⁡</mo><mi>x</mi><mo>&lt;</mo><mi>x</mi><mo>&lt;</mo><mi>tan</mi><mo>⁡</mo><mi>x</mi></mrow><annotation encoding="application/x-tex">\sin x &lt; x &lt; \tan x</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.707em;vertical-align:-0.0391em;"></span><span class="mop">sin</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.5782em;vertical-align:-0.0391em;"></span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">&lt;</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6151em;"></span><span class="mop">tan</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">x</span></span></span></span></p><h2 id="柯西中值定理">柯西中值定理</h2><p><strong>定义</strong>：设函数<br>(1) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 和 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">F(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在闭区间 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">[a, b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span> 上连续，<br>(2) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 和 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">F(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span> 在开区间 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">(a, b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span> 内可导，且<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi mathvariant="normal">∀</mi><mi>x</mi><mo>∈</mo><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><msup><mi>F</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo mathvariant="normal">≠</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\forall x \in (a, b), F&#x27;(x) \neq 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7335em;vertical-align:-0.0391em;"></span><span class="mord">∀</span><span class="mord mathnormal">x</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel"><span class="mrel"><span class="mord vbox"><span class="thinbox"><span class="rlap"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="inner"><span class="mord"><span class="mrel"></span></span></span><span class="fix"></span></span></span></span></span><span class="mrel">=</span></span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，<br>则至少存在一个 <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ξ</mi><mo>∈</mo><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\xi \in (a, b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>，使得</p><p><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mfrac><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo></mrow><mrow><msup><mi>F</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>−</mo><mi>f</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>−</mo><mi>F</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo></mrow></mfrac></mrow><annotation encoding="application/x-tex">\frac{f&#x27;(ξ)}{F&#x27;(ξ)} = \frac{f(b) - f(a)}{F(b) - F(a)}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:2.3649em;vertical-align:-0.936em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.4289em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6779em;"><span style="top:-2.989em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.936em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:2.363em;vertical-align:-0.936em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.427em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.936em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></span></p><p><img src="https://pub-8aa0d697111649baa7f84d6b86206f1c.r2.dev/20250305113950392.png" alt=""></p><details><summary>证明</summary><p>令<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>φ</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">[</mo><mi>f</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo><mo>−</mo><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><mi>F</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>−</mo><mo stretchy="false">[</mo><mi>F</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo><mo>−</mo><mi>F</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\varphi(x) =[f(a)-f(b)]F(x)-[F(a)-F(b)]f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)]</span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)]</span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>，则<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>φ</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\varphi(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">]</mo></mrow><annotation encoding="application/x-tex">[a,b]</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">]</span></span></span></span>上连续，在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">(a,b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>内可导，且<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>φ</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo><mo>=</mo><mi>φ</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\varphi(a) = \varphi(b) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">φ</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，则由罗尔定理，存在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ξ</mi><mo>∈</mo><mo stretchy="false">(</mo><mi>a</mi><mo separator="true">,</mo><mi>b</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">\xi \in (a,b)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">∈</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mclose">)</span></span></span></span>，使得<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>φ</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\varphi&#x27;(\xi) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal">φ</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，即<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mo stretchy="false">[</mo><mi>f</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo><mo>−</mo><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><msup><mi>F</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>−</mo><mo stretchy="false">[</mo><mi>F</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo><mo>−</mo><mi>F</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">[f(a)-f(b)]F&#x27;(ξ)-[F(a)-F(b)]f&#x27;(ξ) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)]</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">[</span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">a</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.13889em;">F</span><span class="mopen">(</span><span class="mord mathnormal">b</span><span class="mclose">)]</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal" style="margin-right:0.04601em;">ξ</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，即<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mfrac><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo></mrow><mrow><msup><mi>F</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>−</mo><mi>f</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo></mrow><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>b</mi><mo stretchy="false">)</mo><mo>−</mo><mi>F</mi><mo stretchy="false">(</mo><mi>a</mi><mo stretchy="false">)</mo></mrow></mfrac></mrow><annotation encoding="application/x-tex">\frac{f&#x27;(ξ)}{F&#x27;(ξ)} = \frac{f(b) - f(a)}{F(b) - F(a)}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.5845em;vertical-align:-0.52em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0645em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.13889em;">F</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6828em;"><span style="top:-2.786em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight" style="margin-right:0.04601em;">ξ</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8278em;"><span style="top:-2.931em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight" style="margin-right:0.04601em;">ξ</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.53em;vertical-align:-0.52em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.01em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.13889em;">F</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">b</span><span class="mclose mtight">)</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight" style="margin-right:0.13889em;">F</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">a</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">b</span><span class="mclose mtight">)</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">a</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></p></details><h2 id="洛必达法则">洛必达法则</h2><p>若 1) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\lim_{x \to x_0} f(x) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0001em;vertical-align:-0.2501em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span>，<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">\lim_{x \to x_0} g(x) = 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0001em;vertical-align:-0.2501em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span><br>2) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">f(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>和<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">g(x)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span></span></span></span>在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>x</mi><mn>0</mn></msub></mrow><annotation encoding="application/x-tex">x_0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.5806em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span>在<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>U</mi><mo stretchy="false">(</mo><msub><mi>x</mi><mn>0</mn></msub><mo separator="true">,</mo><mi>δ</mi><mo stretchy="false">)</mo></mrow><annotation encoding="application/x-tex">U(x_0,δ)</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10903em;">U</span><span class="mopen">(</span><span class="mord"><span class="mord mathnormal">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3011em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal" style="margin-right:0.03785em;">δ</span><span class="mclose">)</span></span></span></span>内可导，且<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>g</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo mathvariant="normal">≠</mo><mn>0</mn></mrow><annotation encoding="application/x-tex">g&#x27;(x) \neq 0</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.0019em;vertical-align:-0.25em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7519em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen">(</span><span class="mord mathnormal">x</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel"><span class="mrel"><span class="mord vbox"><span class="thinbox"><span class="rlap"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="inner"><span class="mord"><span class="mrel"></span></span></span><span class="fix"></span></span></span></span></span><span class="mrel">=</span></span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">0</span></span></span></span><br>3) <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mfrac><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mrow><msup><mi>g</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mfrac></mrow><annotation encoding="application/x-tex">\lim_{x \to x_0} \frac{f&#x27;(x)}{g&#x27;(x)}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.5845em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0645em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6828em;"><span style="top:-2.786em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8278em;"><span style="top:-2.931em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span>存在或为无穷大<br>则<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mrow><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mfrac><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mrow><msup><mi>g</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mfrac></mrow><annotation encoding="application/x-tex">\lim_{x \to x_0} \frac{f(x)}{g(x)} = \lim_{x \to x_0} \frac{f&#x27;(x)}{g&#x27;(x)}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.53em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.01em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.5845em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0645em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6828em;"><span style="top:-2.786em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8278em;"><span style="top:-2.931em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></p><p>[证]根据柯西中值定理<br><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mrow><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mfrac><mrow><mi>f</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>−</mo><mi>f</mi><mo stretchy="false">(</mo><msub><mi>x</mi><mn>0</mn></msub><mo stretchy="false">)</mo></mrow><mrow><mi>g</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>−</mo><mi>g</mi><mo stretchy="false">(</mo><msub><mi>x</mi><mn>0</mn></msub><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mfrac><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo></mrow><mrow><msup><mi>g</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>ξ</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msub><mi>x</mi><mn>0</mn></msub></mrow></msub><mfrac><mrow><msup><mi>f</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mrow><msup><mi>g</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mfrac></mrow><annotation encoding="application/x-tex">\lim_{x \to x_0} \frac{f(x)}{g(x)} = \lim_{x \to x_0} \frac{f(x)-f(x_0)}{g(x)-g(x_0)} = \lim_{x \to x_0} \frac{f&#x27;(ξ)}{g&#x27;(ξ)} = \lim_{x \to x_0} \frac{f&#x27;(x)}{g&#x27;(x)}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1.53em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.01em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.53em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.01em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="mopen mtight">(</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span><span class="mbin mtight">−</span><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="mopen mtight">(</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.5845em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0645em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6828em;"><span style="top:-2.786em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight" style="margin-right:0.04601em;">ξ</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8278em;"><span style="top:-2.931em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight" style="margin-right:0.04601em;">ξ</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.5845em;vertical-align:-0.52em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3173em;"><span style="top:-2.357em;margin-left:0em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight">0</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2501em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0645em;"><span style="top:-2.655em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.03588em;">g</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.6828em;"><span style="top:-2.786em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.485em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight"><span class="mord mathnormal mtight" style="margin-right:0.10764em;">f</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8278em;"><span style="top:-2.931em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">′</span></span></span></span></span></span></span></span></span><span class="mopen mtight">(</span><span class="mord mathnormal mtight">x</span><span class="mclose mtight">)</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.52em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span></span></span></span></p><details><summary>例 求 <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>lim</mi><mo>⁡</mo><mrow><mi>x</mi><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow><mo>(</mo><mi>x</mi><msup><mo>)</mo><mi>sin</mi><mi>x</mi></msup></mrow></math></summary><p>[解] 原式 = <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></msub><msup><mi>e</mi><mrow><mi>sin</mi><mo>⁡</mo><mi>x</mi><mi>ln</mi><mo>⁡</mo><mi>x</mi></mrow></msup><mo>=</mo><msup><mi>e</mi><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></msub><mi>sin</mi><mo>⁡</mo><mi>x</mi><mi>ln</mi><mo>⁡</mo><mi>x</mi></mrow></msup><mo>=</mo><msup><mi>e</mi><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></msub><mi>x</mi><mi>ln</mi><mo>⁡</mo><mi>x</mi></mrow></msup><mo>=</mo><msup><mi>e</mi><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></msub><mfrac><mrow><mi>ln</mi><mo>⁡</mo><mi>x</mi></mrow><mrow><mn>1</mn><mi mathvariant="normal">/</mi><mi>x</mi></mrow></mfrac></mrow></msup><mo>=</mo><msup><mi>e</mi><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></msub><mfrac><mrow><mn>1</mn><mi mathvariant="normal">/</mi><mi>x</mi></mrow><mrow><mo>−</mo><mn>1</mn><mi mathvariant="normal">/</mi><msup><mi>x</mi><mn>2</mn></msup></mrow></mfrac></mrow></msup><mo>=</mo><msup><mi>e</mi><mrow><msub><mrow><mi>lim</mi><mo>⁡</mo></mrow><mrow><mi>x</mi><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></msub><mo>−</mo><mi>x</mi></mrow></msup><mo>=</mo><msup><mi>e</mi><mn>0</mn></msup><mo>=</mo><mn>1</mn></mrow><annotation encoding="application/x-tex">\lim_{x \to 0^+} e^{\sin x \ln x} = e^{\lim_{x \to 0^+} \sin x \ln x} = e^{\lim_{x \to 0^+} x \ln x } = e^{\lim_{x \to 0^+} \frac{\ln x}{1/x}} = e^{\lim_{x \to 0^+} \frac{1/x}{-1/x^2}} = e^{\lim_{x \to 0^+} -x} = e^0 = 1</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.9991em;vertical-align:-0.15em;"></span><span class="mop"><span class="mop">lim</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3419em;"><span style="top:-2.55em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mtight">0</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.7027em;"><span style="top:-2.786em;margin-right:0.0714em;"><span class="pstrut" style="height:2.5em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mbin mtight">+</span></span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mop mtight"><span class="mtight">s</span><span class="mtight">i</span><span class="mtight">n</span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mathnormal mtight">x</span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mop mtight"><span class="mtight">l</span><span class="mtight">n</span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.8491em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mop mtight"><span class="mop mtight"><span class="mtight">l</span><span class="mtight">i</span><span class="mtight">m</span></span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3448em;"><span style="top:-2.3448em;margin-right:0.0714em;"><span class="pstrut" style="height:2.6267em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mtight">0</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8773em;"><span style="top:-2.8773em;margin-right:0.1em;"><span class="pstrut" style="height:2.5833em;"></span><span class="mbin mtight">+</span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2819em;"><span></span></span></span></span></span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mop mtight"><span class="mtight">s</span><span class="mtight">i</span><span class="mtight">n</span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mathnormal mtight">x</span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mop mtight"><span class="mtight">l</span><span class="mtight">n</span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.8491em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mop mtight"><span class="mop mtight"><span class="mtight">l</span><span class="mtight">i</span><span class="mtight">m</span></span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3448em;"><span style="top:-2.3448em;margin-right:0.0714em;"><span class="pstrut" style="height:2.6267em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mtight">0</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8773em;"><span style="top:-2.8773em;margin-right:0.1em;"><span class="pstrut" style="height:2.5833em;"></span><span class="mbin mtight">+</span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2819em;"><span></span></span></span></span></span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mathnormal mtight">x</span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mop mtight"><span class="mtight">l</span><span class="mtight">n</span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.1002em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:1.1002em;"><span style="top:-3.4842em;margin-right:0.05em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mop mtight"><span class="mop mtight"><span class="mtight">l</span><span class="mtight">i</span><span class="mtight">m</span></span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3448em;"><span style="top:-2.3448em;margin-right:0.0714em;"><span class="pstrut" style="height:2.6267em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mtight">0</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8773em;"><span style="top:-2.8773em;margin-right:0.1em;"><span class="pstrut" style="height:2.5833em;"></span><span class="mbin mtight">+</span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2819em;"><span></span></span></span></span></span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mtight"><span class="mopen nulldelimiter sizing reset-size3 size6"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.88em;"><span style="top:-2.6408em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1/</span><span class="mord mathnormal mtight">x</span></span></span></span><span style="top:-3.2255em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line mtight" style="border-bottom-width:0.049em;"></span></span><span style="top:-3.384em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mop mtight"><span class="mtight">l</span><span class="mtight">n</span></span><span class="mspace mtight" style="margin-right:0.2453em;"></span><span class="mord mathnormal mtight">x</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.5378em;"><span></span></span></span></span></span><span class="mclose nulldelimiter sizing reset-size3 size6"></span></span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.3049em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:1.3049em;"><span style="top:-3.5784em;margin-right:0.05em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mop mtight"><span class="mop mtight"><span class="mtight">l</span><span class="mtight">i</span><span class="mtight">m</span></span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3448em;"><span style="top:-2.3448em;margin-right:0.0714em;"><span class="pstrut" style="height:2.6267em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mtight">0</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8773em;"><span style="top:-2.8773em;margin-right:0.1em;"><span class="pstrut" style="height:2.5833em;"></span><span class="mbin mtight">+</span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2819em;"><span></span></span></span></span></span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mtight"><span class="mopen nulldelimiter sizing reset-size3 size6"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.0378em;"><span style="top:-2.5062em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">−</span><span class="mord mtight">1/</span><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.9384em;"><span style="top:-2.9384em;margin-right:0.1em;"><span class="pstrut" style="height:2.6444em;"></span><span class="mord mtight">2</span></span></span></span></span></span></span></span></span></span><span style="top:-3.2255em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line mtight" style="border-bottom-width:0.049em;"></span></span><span style="top:-3.5021em;"><span class="pstrut" style="height:3em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mtight">1/</span><span class="mord mathnormal mtight">x</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.6724em;"><span></span></span></span></span></span><span class="mclose nulldelimiter sizing reset-size3 size6"></span></span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.8491em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8491em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mop mtight"><span class="mop mtight"><span class="mtight">l</span><span class="mtight">i</span><span class="mtight">m</span></span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3448em;"><span style="top:-2.3448em;margin-right:0.0714em;"><span class="pstrut" style="height:2.6267em;"></span><span class="sizing reset-size3 size1 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">x</span><span class="mrel mtight">→</span><span class="mord mtight"><span class="mord mtight">0</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8773em;"><span style="top:-2.8773em;margin-right:0.1em;"><span class="pstrut" style="height:2.5833em;"></span><span class="mbin mtight">+</span></span></span></span></span></span></span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.2819em;"><span></span></span></span></span></span></span><span class="mspace mtight" style="margin-right:0.1952em;"></span><span class="mord mtight">−</span><span class="mord mathnormal mtight">x</span></span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.8141em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8141em;"><span style="top:-3.063em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">1</span></span></span></span></p></details>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;微分中值定理与导数的应用&lt;/h1&gt;
&lt;h2 id=&quot;罗尔定理&quot;&gt;罗尔定理&lt;/h2&gt;
&lt;p&gt;定义：设函数&lt;br&gt;
(1) &lt;span class=&quot;katex&quot;&gt;&lt;span class=&quot;katex-mathml&quot;&gt;&lt;math xmlns=&quot;http://www.w3.or</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>Ubuntu扩展根目录空间</title>
    <link href="http://example.com/post/78f27254.html"/>
    <id>http://example.com/post/78f27254.html</id>
    <published>2025-02-21T10:54:06.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>Ubuntu扩展根目录空间（扩展原有分区）</h1><p>发表于 2021-12-01 更新于 2024-05-30 阅读次数： 本文字数： 1.6k 阅读时长 ≈ 6 分钟</p><h1><a href="about:blank#0-%E6%A6%82%E5%BF%B5%E8%AF%B4%E6%98%8E" title="0.概念说明"></a>0.概念说明</h1><p>一切开始的开始 先说明一些概念</p><blockquote><p><strong>物理卷（Physical Volume）即PV：</strong> 物理卷就是指硬盘分区或从逻辑上与磁盘分区具有同样功能的设备(如RAID)，是LVM的基本存储逻辑块，但和基本的物理存储介质（如分区、磁盘等）比较，却包含有与LVM相关的管理参数。<br><strong>卷组（Volume Group）即VG：</strong> LVM卷组类似于非LVM系统中的物理硬盘，其由物理卷组成。可以在卷组上创建一个或多个“LVM分区”（逻辑卷），LVM卷组由一个或多个物理卷组成。<br><strong>逻辑卷（Logical Volume）即LV：</strong> LVM的逻辑卷类似于非LVM系统中的硬盘分区，在逻辑卷之上可以建立文件系统(比如/home或者/usr等)。</p></blockquote><p>总之 LV建立在VG之上，VG建立在PV之上，是PV的集合，PV即物理卷。</p><p><strong>本文的总体思路为： 扩容PV-&gt; 扩容LV -&gt; 扩容根目录空间</strong></p><h1><a href="about:blank#1-VM%E6%B7%BB%E5%8A%A0%E7%A9%BA%E9%97%B4" title="1.VM添加空间"></a>1.VM添加空间</h1><p>使用vmware增加空间 ↓<br><img src="https://syra-ti.icu/images/posts/6bcae82012ad45d6afcd2a9a55bda7a4.png" alt="在这里插入图片描述"></p><h1><a href="about:blank#2-%E4%BD%BF%E7%94%A8fdisk%E6%89%A9%E5%B1%95%E5%8E%9F%E6%9C%89%E5%88%86%E5%8C%BA" title="2.使用fdisk扩展原有分区"></a>2.使用fdisk扩展原有分区</h1><p>此处参考了<a href="https://www.linuxprobe.com/linux-fdisk-size.html">Linux下使用fdisk扩展分区容量</a>，原文关键部分摘录如下</p><blockquote><p>对/dev/sda4进行扩容</p></blockquote><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br></pre></td><td class="code"><pre><span class="line">[root@linuxprobe ~]: fdisk /dev/sda #对/dev/sda进行操作 </span><br><span class="line">WARNING: DOS-compatible mode is deprecated. It&#x27;s strongly recommended to </span><br><span class="line">         switch off the mode (command &#x27;c&#x27;) and change display units to </span><br><span class="line">         sectors (command &#x27;u&#x27;). </span><br><span class="line">Command (m for help): p        #查看分区表信息 </span><br><span class="line">Disk /dev/sda: 32.2 GB, 32212254720 bytes </span><br><span class="line">255 heads, 63 sectors/track, 3916 cylinders </span><br><span class="line">Units = cylinders of 16065 * 512 = 8225280 bytes </span><br><span class="line">Sector size (logical/physical): 512 bytes / 512 bytes </span><br><span class="line">I/O size (minimum/optimal): 512 bytes / 512 bytes </span><br><span class="line">Disk identifier: 0x0005210c </span><br><span class="line">   Device Boot      Start         End      Blocks   Id  System </span><br><span class="line">/dev/sda1   *           1          26      204800   83  Linux </span><br><span class="line">Partition 1 does not end on cylinder boundary. </span><br><span class="line">/dev/sda2              26        1301    10240000   83  Linux </span><br><span class="line">/dev/sda3            1301        1497     1572864   82  Linux swap / Solaris </span><br><span class="line">/dev/sda4            1497        2611     8952832   83  Linux </span><br><span class="line">Command (m for help): d           #删除分区 </span><br><span class="line">Partition number (1-4): 4         #删除需要扩容的分区（这里为sda4） </span><br><span class="line">Command (m for help): p       #再次查看分区信息，/dev/sda4已被删除 </span><br><span class="line">Disk /dev/sda: 32.2 GB, 32212254720 bytes </span><br><span class="line">255 heads, 63 sectors/track, 3916 cylinders </span><br><span class="line">Units = cylinders of 16065 * 512 = 8225280 bytes </span><br><span class="line">Sector size (logical/physical): 512 bytes / 512 bytes </span><br><span class="line">I/O size (minimum/optimal): 512 bytes / 512 bytes </span><br><span class="line">Disk identifier: 0x0005210c </span><br><span class="line">   Device Boot      Start         End      Blocks   Id  System </span><br><span class="line">/dev/sda1   *           1          26      204800   83  Linux </span><br><span class="line">Partition 1 does not end on cylinder boundary. </span><br><span class="line">/dev/sda2              26        1301    10240000   83  Linux </span><br><span class="line">/dev/sda3            1301        1497     1572864   82  Linux swap / Solaris </span><br><span class="line">Command (m for help): n      #创建新的分区 </span><br><span class="line">Command action </span><br><span class="line">   e   extended </span><br><span class="line">   p   primary partition (1-4) </span><br><span class="line">p             #创建为主分区 </span><br><span class="line">Selected partition 4 </span><br><span class="line">First cylinder (1497-3916, default 1497):          #经对比，正好和上一个磁盘柱一致，默认即可 </span><br><span class="line">Using default value 1497 </span><br><span class="line">Last cylinder, +cylinders or +size&#123;K,M,G&#125; (1497-3916, default 3916):  </span><br><span class="line">Using default value 3916              #直接默认就可以 </span><br><span class="line">Command (m for help): p               #查看分区表信息 </span><br><span class="line">Disk /dev/sda: 32.2 GB, 32212254720 bytes </span><br><span class="line">255 heads, 63 sectors/track, 3916 cylinders </span><br><span class="line">Units = cylinders of 16065 * 512 = 8225280 bytes </span><br><span class="line">Sector size (logical/physical): 512 bytes / 512 bytes </span><br><span class="line">I/O size (minimum/optimal): 512 bytes / 512 bytes </span><br><span class="line">Disk identifier: 0x0005210c </span><br><span class="line">   Device Boot      Start         End      Blocks   Id  System </span><br><span class="line">/dev/sda1   *           1          26      204800   83  Linux </span><br><span class="line">Partition 1 does not end on cylinder boundary. </span><br><span class="line">/dev/sda2              26        1301    10240000   83  Linux </span><br><span class="line">/dev/sda3            1301        1497     1572864   82  Linux swap / Solaris </span><br><span class="line">/dev/sda4            1497        3916    19436582   83  Linux </span><br><span class="line">Command (m for help): wp       #保存并退出，如果创建有误，直接退出不要保存即可 </span><br><span class="line">The partition table has been altered! </span><br><span class="line">Calling ioctl() to re-read partition table. </span><br><span class="line">WARNING: Re-reading the partition table failed with error 16: Device or resource busy. </span><br><span class="line">The kernel still uses the old table. The new table will be used at </span><br><span class="line">the next reboot or after you run partprobe(8) or kpartx(8) </span><br><span class="line">Syncing disks.</span><br></pre></td></tr></table></figure><h1><a href="about:blank#3-%E5%88%B7%E6%96%B0PV%E7%A9%BA%E9%97%B4" title="3.刷新PV空间"></a>3.刷新PV空间</h1><p>对分区扩容完成后，会发现空间依旧没有增加，此时需要先刷新pv大小，使用<code>pvresize</code>:</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br></pre></td><td class="code"><pre><span class="line">[root@syra-ti_ubuntu~]: pvdisplay #先列出pv </span><br><span class="line">  --- Physical volume --- </span><br><span class="line">  PV Name               /dev/sda4 </span><br><span class="line">  VG Name               ubuntu-vg </span><br><span class="line">  PV Size               &amp;lt;19.00 GiB / not usable 16.50 KiB </span><br><span class="line">  Allocatable           yes (but full) </span><br><span class="line">  PE Size               4.00 MiB </span><br><span class="line">  Total PE              9983 </span><br><span class="line">  Free PE               0 </span><br><span class="line">  Allocated PE          9983 </span><br><span class="line">  PV UUID               2CF0fb-auL8-N1Xk-Lpo1-pdzo-MLN5-R0QAIX </span><br><span class="line">   </span><br><span class="line">[root@syra-ti_ubuntu~]: pvresize /dev/sda4 #调用pvresize进行刷新 </span><br><span class="line">  Physical volume &quot;/dev/sda3&quot; changed </span><br><span class="line">  1 physical volume(s) resized / 0 physical volume(s) not resized </span><br><span class="line">[root@syra-ti_ubuntu~]: pvdisplay #再次查看pv大小 发现pv大小已经正常 </span><br><span class="line">  --- Physical volume --- </span><br><span class="line">  PV Name               /dev/sda4 </span><br><span class="line">  VG Name               ubuntu-vg </span><br><span class="line">  PV Size               &amp;lt;39.00 GiB / not usable 16.50 KiB </span><br><span class="line">  Allocatable           yes (but full) </span><br><span class="line">  PE Size               4.00 MiB </span><br><span class="line">  Total PE              9983 </span><br><span class="line">  Free PE               0 </span><br><span class="line">  Allocated PE          9983 </span><br><span class="line">  PV UUID               2CF0fb-auL8-N1Xk-Lpo1-pdzo-MLN5-R0QAIX </span><br></pre></td></tr></table></figure><h1><a href="about:blank#4-%E4%B8%BALV%E5%A2%9E%E5%8A%A0%E7%A9%BA%E9%97%B4" title="4.为LV增加空间"></a>4.为LV增加空间</h1><p>对pv扩容完成后，会发现lv的空间依旧没有增加，此时需要扩展lv大小，使用<code>lvextend</code>:</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br></pre></td><td class="code"><pre><span class="line">[root@syra-ti_ubuntu~]: lvdisplay #列出lv信息 发现lv空间没有增加 </span><br><span class="line">  --- Logical volume --- </span><br><span class="line">  LV Path                /dev/ubuntu-vg/ubuntu-lv </span><br><span class="line">  LV Name                ubuntu-lv </span><br><span class="line">  VG Name                ubuntu-vg </span><br><span class="line">  LV UUID                3THGqb-Me9D-KFEK-QxT5-dP8Y-hUqa-knbAa3 </span><br><span class="line">  LV Write Access        read/write </span><br><span class="line">  LV Creation host, time ubuntu-server, 2021-10-12 06:49:31 +0000 </span><br><span class="line">  LV Status              available </span><br><span class="line">&lt;span class=&quot;meta prompt_&quot;&gt;  # &lt;/span&gt;&lt;span class=&quot;language-bash&quot;&gt;open                 1&lt;/span&gt; </span><br><span class="line">  LV Size                &amp;lt;19.00 GiB </span><br><span class="line">  Current LE             9983 </span><br><span class="line">  Segments               1 </span><br><span class="line">  Allocation             inherit </span><br><span class="line">  Read ahead sectors     auto </span><br><span class="line">  - currently set to     256 </span><br><span class="line">  Block device           253:0 </span><br><span class="line">[root@syra-ti_ubuntu~]: lvextend -L +20G /dev/ubuntu-vg/ubuntu-lv /dev/sda4 #调用lvextend进行扩容 </span><br><span class="line">[root@syra-ti_ubuntu~]: lvdisplay #再次列出lv信息 发现lv空间已经增加 </span><br><span class="line">  --- Logical volume --- </span><br><span class="line">  LV Path                /dev/ubuntu-vg/ubuntu-lv </span><br><span class="line">  LV Name                ubuntu-lv </span><br><span class="line">  VG Name                ubuntu-vg </span><br><span class="line">  LV UUID                3THGqb-Me9D-KFEK-QxT5-dP8Y-hUqa-knbAa3 </span><br><span class="line">  LV Write Access        read/write </span><br><span class="line">  LV Creation host, time ubuntu-server, 2021-10-12 06:49:31 +0000 </span><br><span class="line">  LV Status              available </span><br><span class="line">&lt;span class=&quot;meta prompt_&quot;&gt;  # &lt;/span&gt;&lt;span class=&quot;language-bash&quot;&gt;open                 1&lt;/span&gt; </span><br><span class="line">  LV Size                &amp;lt;39.00 GiB </span><br><span class="line">  Current LE             9983 </span><br><span class="line">  Segments               1 </span><br><span class="line">  Allocation             inherit </span><br><span class="line">  Read ahead sectors     auto </span><br><span class="line">  - currently set to     256 </span><br><span class="line">  Block device           253:0 </span><br></pre></td></tr></table></figure><h1><a href="about:blank#5-%E6%89%A9%E5%B1%95%E6%A0%B9%E7%9B%AE%E5%BD%95%E7%A9%BA%E9%97%B4" title="5.扩展根目录空间"></a>5.扩展根目录空间</h1><p>对lv扩容完成后，会发现根目录的空间依旧没有增加，此时需要刷新根目录大小，使用<code>resize2fs</code>:</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br></pre></td><td class="code"><pre><span class="line">[root@syra-ti_ubuntu~]: df -h #发现/根目录空间还是没有增加 </span><br><span class="line">Filesystem                         Size  Used Avail Use% Mounted on </span><br><span class="line">udev                               1.9G     0  1.9G   0% /dev </span><br><span class="line">tmpfs                              393M  1.8M  391M   1% /run </span><br><span class="line">/dev/mapper/ubuntu--vg-ubuntu--lv   19G   18G   19G  99% / </span><br><span class="line">tmpfs                              2.0G     0  2.0G   0% /dev/shm </span><br><span class="line">tmpfs                              5.0M     0  5.0M   0% /run/lock </span><br><span class="line">tmpfs                              2.0G     0  2.0G   0% /sys/fs/cgroup </span><br><span class="line">/dev/loop0                          56M   56M     0 100% /snap/core18/2128 </span><br><span class="line">/dev/loop1                          56M   56M     0 100% /snap/core18/2253 </span><br><span class="line">/dev/loop3                          43M   43M     0 100% /snap/snapd/14066 </span><br><span class="line">/dev/loop2                         117M  117M     0 100% /snap/docker/1125 </span><br><span class="line">/dev/loop4                          33M   33M     0 100% /snap/snapd/13270 </span><br><span class="line">/dev/sda2                          976M  150M  759M  17% /boot </span><br><span class="line">tmpfs                              393M     0  393M   0% /run/user/0 </span><br><span class="line">[root@syra-ti_ubuntu~]: resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv #使用resize2fs进行刷新 </span><br><span class="line">resize2fs 1.44.1 (24-Mar-2018) </span><br><span class="line">Filesystem at /dev/mapper/ubuntu--vg-ubuntu--lv is mounted on /; on-line resizing required </span><br><span class="line">old_desc_blocks = 3, new_desc_blocks = 5 </span><br><span class="line">The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 10222592 (4k) blocks long. </span><br><span class="line">[root@syra-ti_ubuntu~]: df -h #再次查看，发现/根目录空间已经增加 </span><br><span class="line">Filesystem                         Size  Used Avail Use% Mounted on </span><br><span class="line">udev                               1.9G     0  1.9G   0% /dev </span><br><span class="line">tmpfs                              393M  1.8M  391M   1% /run </span><br><span class="line">/dev/mapper/ubuntu--vg-ubuntu--lv   39G   18G   19G  49% / </span><br><span class="line">tmpfs                              2.0G     0  2.0G   0% /dev/shm </span><br><span class="line">tmpfs                              5.0M     0  5.0M   0% /run/lock </span><br><span class="line">tmpfs                              2.0G     0  2.0G   0% /sys/fs/cgroup </span><br><span class="line">/dev/loop0                          56M   56M     0 100% /snap/core18/2128 </span><br><span class="line">/dev/loop1                          56M   56M     0 100% /snap/core18/2253 </span><br><span class="line">/dev/loop3                          43M   43M     0 100% /snap/snapd/14066 </span><br><span class="line">/dev/loop2                         117M  117M     0 100% /snap/docker/1125 </span><br><span class="line">/dev/loop4                          33M   33M     0 100% /snap/snapd/13270 </span><br><span class="line">/dev/sda2                          976M  150M  759M  17% /boot </span><br><span class="line">tmpfs                              393M     0  393M   0% /run/user/0 </span><br></pre></td></tr></table></figure><p>以上！まいど～</p><hr><p>本文转自 <a href="https://syra-ti.icu/ddf76f824c86.html">https://syra-ti.icu/ddf76f824c86.html</a>，如有侵权，请联系删除。</p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;Ubuntu扩展根目录空间（扩展原有分区）&lt;/h1&gt;
&lt;p&gt;发表于 2021-12-01 更新于 2024-05-30 阅读次数： 本文字数： 1.6k 阅读时长 ≈ 6 分钟&lt;/p&gt;
&lt;h1&gt;&lt;a href=&quot;about:blank#0-%E6%A6%82%E5%BF%</summary>
      
    
    
    
    
  </entry>
  
  <entry>
    <title>ArduinoJson库基础应用</title>
    <link href="http://example.com/post/43460f90.html"/>
    <id>http://example.com/post/43460f90.html</id>
    <published>2025-02-12T11:19:21.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<blockquote><p><strong>声明</strong>：此文章由 AI 生成，内容不保证正确。</p></blockquote><h1>使用ArduinoJson库的完整指南</h1><p><code>ArduinoJson</code>是一个功能强大且高效的库，用于在Arduino和其他嵌入式平台上解析、生成和操作JSON数据。本文将指导您如何安装、配置和使用<code>ArduinoJson</code>库。</p><hr><h2 id="目录">目录</h2><ol><li><a href="#%E5%AE%89%E8%A3%85ArduinoJson%E5%BA%93">安装ArduinoJson库</a></li><li><a href="#JSON%E5%9F%BA%E7%A1%80">JSON基础</a></li><li><a href="#%E5%88%9B%E5%BB%BA%E5%92%8C%E6%93%8D%E4%BD%9CJSON%E5%AF%B9%E8%B1%A1">创建和操作JSON对象</a></li><li><a href="#%E8%A7%A3%E6%9E%90JSON%E6%95%B0%E6%8D%AE">解析JSON数据</a></li><li><a href="#%E7%94%9F%E6%88%90JSON%E6%95%B0%E6%8D%AE">生成JSON数据</a></li><li><a href="#%E5%86%85%E5%AD%98%E7%AE%A1%E7%90%86%E4%B8%8E%E4%BC%98%E5%8C%96">内存管理与优化</a></li><li><a href="#%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E4%B8%8E%E8%A7%A3%E5%86%B3%E6%96%B9%E6%B3%95">常见问题与解决方法</a></li><li><a href="#%E4%BB%A3%E7%A0%81%E7%A4%BA%E4%BE%8B">代码示例</a></li></ol><hr><h2 id="安装ArduinoJson库">安装ArduinoJson库</h2><h3 id="1-使用Arduino-IDE的库管理器">1. 使用Arduino IDE的库管理器</h3><ol><li>打开Arduino IDE。</li><li>点击菜单栏中的<code>工具 -&gt; 管理库</code>。</li><li>在搜索框中输入<code>ArduinoJson</code>。</li><li>找到<code>ArduinoJson</code>库，点击<code>安装</code>按钮。</li></ol><h3 id="2-手动安装">2. 手动安装</h3><ol><li>从<a href="https://github.com/bblanchon/ArduinoJson">ArduinoJson的GitHub仓库</a>下载最新版本的库。</li><li>解压下载的文件。</li><li>将解压后的文件夹复制到Arduino的<code>libraries</code>目录中（通常位于<code>Arduino/libraries</code>）。</li><li>重启Arduino IDE。</li></ol><hr><h2 id="JSON基础">JSON基础</h2><p>JSON（JavaScript Object Notation）是一种轻量级的数据交换格式，广泛用于数据通信。以下是JSON的基本结构：</p><ul><li><strong>键值对</strong>：<code>&quot;key&quot;: &quot;value&quot;</code></li><li><strong>数组</strong>：<code>[value1, value2, value3]</code></li><li><strong>嵌套对象</strong>：<code>&#123;&quot;key&quot;: &#123;&quot;subkey&quot;: &quot;subvalue&quot;&#125;&#125;</code></li></ul><p>示例：</p><figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">&#123;</span></span><br><span class="line">  <span class="attr">&quot;sensor&quot;</span><span class="punctuation">:</span> <span class="string">&quot;gps&quot;</span><span class="punctuation">,</span></span><br><span class="line">  <span class="attr">&quot;time&quot;</span><span class="punctuation">:</span> <span class="number">1351824120</span><span class="punctuation">,</span></span><br><span class="line">  <span class="attr">&quot;data&quot;</span><span class="punctuation">:</span> <span class="punctuation">[</span><span class="number">48.756080</span><span class="punctuation">,</span> <span class="number">2.302038</span><span class="punctuation">]</span></span><br><span class="line"><span class="punctuation">&#125;</span></span><br></pre></td></tr></table></figure><hr><h2 id="创建和操作JSON对象">创建和操作JSON对象</h2><h3 id="1-创建JSON对象">1. 创建JSON对象</h3><p>使用<code>JsonDocument</code>类创建和操作JSON对象。</p><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;ArduinoJson.h&gt;</span></span></span><br><span class="line"></span><br><span class="line"><span class="function"><span class="type">void</span> <span class="title">setup</span><span class="params">()</span> </span>&#123;</span><br><span class="line">  <span class="comment">// 初始化串口</span></span><br><span class="line">  Serial.<span class="built_in">begin</span>(<span class="number">9600</span>);</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 创建一个动态JSON文档</span></span><br><span class="line">  JsonDocument doc;</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 添加键值对</span></span><br><span class="line">  doc[<span class="string">&quot;sensor&quot;</span>] = <span class="string">&quot;gps&quot;</span>;</span><br><span class="line">  doc[<span class="string">&quot;time&quot;</span>] = <span class="number">1351824120</span>;</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 添加数组</span></span><br><span class="line">  JsonArray data = doc.<span class="built_in">createNestedArray</span>(<span class="string">&quot;data&quot;</span>);</span><br><span class="line">  data.<span class="built_in">add</span>(<span class="number">48.756080</span>);</span><br><span class="line">  data.<span class="built_in">add</span>(<span class="number">2.302038</span>);</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 打印JSON对象</span></span><br><span class="line">  <span class="built_in">serializeJson</span>(doc, Serial);</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><p>输出：</p><figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">&#123;</span><span class="attr">&quot;sensor&quot;</span><span class="punctuation">:</span><span class="string">&quot;gps&quot;</span><span class="punctuation">,</span><span class="attr">&quot;time&quot;</span><span class="punctuation">:</span><span class="number">1351824120</span><span class="punctuation">,</span><span class="attr">&quot;data&quot;</span><span class="punctuation">:</span><span class="punctuation">[</span><span class="number">48.756080</span><span class="punctuation">,</span><span class="number">2.302038</span><span class="punctuation">]</span><span class="punctuation">&#125;</span></span><br></pre></td></tr></table></figure><h3 id="2-修改JSON对象">2. 修改JSON对象</h3><p>可以直接通过键名修改JSON对象的值：</p><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">doc[<span class="string">&quot;sensor&quot;</span>] = <span class="string">&quot;temperature&quot;</span>;</span><br><span class="line">doc[<span class="string">&quot;data&quot;</span>][<span class="number">0</span>] = <span class="number">25.5</span>;</span><br></pre></td></tr></table></figure><hr><h2 id="解析JSON数据">解析JSON数据</h2><h3 id="1-从字符串解析JSON">1. 从字符串解析JSON</h3><p>使用<code>deserializeJson</code>函数解析JSON字符串。</p><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;ArduinoJson.h&gt;</span></span></span><br><span class="line"></span><br><span class="line"><span class="function"><span class="type">void</span> <span class="title">setup</span><span class="params">()</span> </span>&#123;</span><br><span class="line">  Serial.<span class="built_in">begin</span>(<span class="number">9600</span>);</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 定义JSON输入字符串</span></span><br><span class="line">  String input = <span class="string">&quot;&#123;\&quot;sensor\&quot;:\&quot;gps\&quot;,\&quot;time\&quot;:1351824120,\&quot;data\&quot;:[48.756080,2.302038]&#125;&quot;</span>;</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 创建JSON文档</span></span><br><span class="line">  JsonDocument doc;</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 解析JSON字符串</span></span><br><span class="line">  DeserializationError error = <span class="built_in">deserializeJson</span>(doc, input);</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 检查解析是否成功</span></span><br><span class="line">  <span class="keyword">if</span> (error) &#123;</span><br><span class="line">    Serial.<span class="built_in">print</span>(<span class="string">&quot;解析错误: &quot;</span>);</span><br><span class="line">    Serial.<span class="built_in">println</span>(error.<span class="built_in">c_str</span>());</span><br><span class="line">    <span class="keyword">return</span>;</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 提取数据</span></span><br><span class="line">  <span class="type">const</span> <span class="type">char</span>* sensor = doc[<span class="string">&quot;sensor&quot;</span>];</span><br><span class="line">  <span class="type">long</span> time = doc[<span class="string">&quot;time&quot;</span>];</span><br><span class="line">  <span class="type">double</span> latitude = doc[<span class="string">&quot;data&quot;</span>][<span class="number">0</span>];</span><br><span class="line">  <span class="type">double</span> longitude = doc[<span class="string">&quot;data&quot;</span>][<span class="number">1</span>];</span><br><span class="line"></span><br><span class="line">  <span class="comment">// 打印解析结果</span></span><br><span class="line">  Serial.<span class="built_in">println</span>(sensor);</span><br><span class="line">  Serial.<span class="built_in">println</span>(time);</span><br><span class="line">  Serial.<span class="built_in">println</span>(latitude);</span><br><span class="line">  Serial.<span class="built_in">println</span>(longitude);</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><hr><h2 id="生成JSON数据">生成JSON数据</h2><h3 id="1-生成紧凑格式的JSON">1. 生成紧凑格式的JSON</h3><p>使用<code>serializeJson</code>生成紧凑格式的JSON字符串。</p><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">String output;</span><br><span class="line"><span class="built_in">serializeJson</span>(doc, output);</span><br><span class="line">Serial.<span class="built_in">println</span>(output);</span><br></pre></td></tr></table></figure><h3 id="2-生成美化格式的JSON">2. 生成美化格式的JSON</h3><p>使用<code>serializeJsonPretty</code>生成美化格式的JSON字符串。</p><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">String output;</span><br><span class="line"><span class="built_in">serializeJsonPretty</span>(doc, output);</span><br><span class="line">Serial.<span class="built_in">println</span>(output);</span><br></pre></td></tr></table></figure><hr><h2 id="内存管理与优化">内存管理与优化</h2><h3 id="1-使用StaticJsonDocument">1. 使用<code>StaticJsonDocument</code></h3><p><code>StaticJsonDocument</code>用于分配固定大小的内存缓冲区，适合资源受限的单片机。</p><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">StaticJsonDocument&lt;<span class="number">200</span>&gt; doc;  <span class="comment">// 分配200字节的缓冲区</span></span><br></pre></td></tr></table></figure><h3 id="2-使用serialized-优化字符串存储">2. 使用<code>serialized()</code>优化字符串存储</h3><p>使用<code>serialized()</code>可以避免复制字符串内容，从而减少内存使用。</p><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">doc[<span class="string">&quot;sensor&quot;</span>] = <span class="built_in">serialized</span>(<span class="string">&quot;gps&quot;</span>);</span><br></pre></td></tr></table></figure><h3 id="3-清理内存">3. 清理内存</h3><p>在完成JSON操作后，调用<code>doc.clear()</code>释放内存。</p><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">doc.<span class="built_in">clear</span>();</span><br></pre></td></tr></table></figure><hr><h2 id="常见问题与解决方法">常见问题与解决方法</h2><h3 id="1-解析失败">1. 解析失败</h3><ul><li><strong>问题</strong>：<code>deserializeJson</code>返回错误。</li><li><strong>解决方法</strong>：检查输入的JSON字符串是否格式正确，确保没有多余的逗号或缺少引号。</li></ul><h3 id="2-内存不足">2. 内存不足</h3><ul><li><strong>问题</strong>：程序运行时出现内存不足错误。</li><li><strong>解决方法</strong>：<ul><li>使用<code>StaticJsonDocument</code>手动分配固定大小的缓冲区。</li><li>减少JSON对象的大小，移除不必要的数据。</li></ul></li></ul><h3 id="3-String与JsonDocument的交互问题">3. <code>String</code>与<code>JsonDocument</code>的交互问题</h3><ul><li><strong>问题</strong>：使用<code>String</code>作为键或值时，内存使用增加。</li><li><strong>解决方法</strong>：尽量避免使用<code>String</code>，改用<code>char*</code>或<code>serialized()</code>。</li></ul><hr><h2 id="参考资料">参考资料</h2><ul><li><a href="https://arduinojson.org/">ArduinoJson官方文档</a></li><li><a href="https://github.com/bblanchon/ArduinoJson">ArduinoJson GitHub仓库</a></li></ul><hr><p>#以下是一个完整的Arduino代码示例，展示如何从串口接收JSON数据，解析其中的参数<code>a</code>和<code>b</code>，并将它们保存到变量中。我们将使用<code>ArduinoJson</code>库来解析JSON数据。</p><hr><h2 id="代码示例">代码示例</h2><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;ArduinoJson.h&gt;</span></span></span><br><span class="line"></span><br><span class="line"><span class="comment">// 定义变量a和b</span></span><br><span class="line"><span class="type">int</span> a = <span class="number">0</span>;</span><br><span class="line"><span class="type">int</span> b = <span class="number">0</span>;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="type">void</span> <span class="title">setup</span><span class="params">()</span> </span>&#123;</span><br><span class="line">  <span class="comment">// 初始化串口</span></span><br><span class="line">  Serial.<span class="built_in">begin</span>(<span class="number">9600</span>);</span><br><span class="line">  <span class="keyword">while</span> (!Serial) &#123;</span><br><span class="line">    ; <span class="comment">// 等待串口初始化完成（仅适用于某些开发板）</span></span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  Serial.<span class="built_in">println</span>(<span class="string">&quot;请输入JSON数据，例如：&#123;\&quot;a\&quot;:10,\&quot;b\&quot;:20&#125;&quot;</span>);</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="type">void</span> <span class="title">loop</span><span class="params">()</span> </span>&#123;</span><br><span class="line">  <span class="comment">// 检查是否有数据可读</span></span><br><span class="line">  <span class="keyword">if</span> (Serial.<span class="built_in">available</span>() &gt; <span class="number">0</span>) &#123;</span><br><span class="line">    <span class="comment">// 读取串口数据</span></span><br><span class="line">    String input = Serial.<span class="built_in">readStringUntil</span>(<span class="string">&#x27;\n&#x27;</span>);</span><br><span class="line">    input.<span class="built_in">trim</span>(); <span class="comment">// 去除多余的空格或换行符</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">// 创建JSON文档</span></span><br><span class="line">    StaticJsonDocument&lt;<span class="number">200</span>&gt; doc; <span class="comment">// 分配200字节的缓冲区</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">// 解析JSON数据</span></span><br><span class="line">    DeserializationError error = <span class="built_in">deserializeJson</span>(doc, input);</span><br><span class="line"></span><br><span class="line">    <span class="comment">// 检查解析是否成功</span></span><br><span class="line">    <span class="keyword">if</span> (error) &#123;</span><br><span class="line">      Serial.<span class="built_in">print</span>(<span class="string">&quot;解析错误: &quot;</span>);</span><br><span class="line">      Serial.<span class="built_in">println</span>(error.<span class="built_in">c_str</span>());</span><br><span class="line">      <span class="keyword">return</span>;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="comment">// 提取参数a和b</span></span><br><span class="line">    <span class="keyword">if</span> (doc.<span class="built_in">containsKey</span>(<span class="string">&quot;a&quot;</span>) &amp;&amp; doc.<span class="built_in">containsKey</span>(<span class="string">&quot;b&quot;</span>)) &#123;</span><br><span class="line">      a = doc[<span class="string">&quot;a&quot;</span>]; <span class="comment">// 提取参数a</span></span><br><span class="line">      b = doc[<span class="string">&quot;b&quot;</span>]; <span class="comment">// 提取参数b</span></span><br><span class="line"></span><br><span class="line">      <span class="comment">// 打印提取的值</span></span><br><span class="line">      Serial.<span class="built_in">print</span>(<span class="string">&quot;成功解析: a = &quot;</span>);</span><br><span class="line">      Serial.<span class="built_in">print</span>(a);</span><br><span class="line">      Serial.<span class="built_in">print</span>(<span class="string">&quot;, b = &quot;</span>);</span><br><span class="line">      Serial.<span class="built_in">println</span>(b);</span><br><span class="line">    &#125; <span class="keyword">else</span> &#123;</span><br><span class="line">      Serial.<span class="built_in">println</span>(<span class="string">&quot;JSON中缺少参数a或b&quot;</span>);</span><br><span class="line">    &#125;</span><br><span class="line">  &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><hr><h3 id="代码解析"><strong>代码解析</strong></h3><h4 id="1-初始化串口"><strong>1. 初始化串口</strong></h4><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">Serial.<span class="built_in">begin</span>(<span class="number">9600</span>);</span><br><span class="line"><span class="keyword">while</span> (!Serial) &#123;</span><br><span class="line">  ; <span class="comment">// 等待串口初始化完成（仅适用于某些开发板）</span></span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><ul><li><code>Serial.begin(9600)</code>：设置串口波特率为9600。</li><li><code>while (!Serial)</code>：等待串口初始化完成，适用于某些需要手动连接串口的开发板（如Arduino Leonardo）。</li></ul><hr><h4 id="2-定义变量"><strong>2. 定义变量</strong></h4><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="type">int</span> a = <span class="number">0</span>;</span><br><span class="line"><span class="type">int</span> b = <span class="number">0</span>;</span><br></pre></td></tr></table></figure><ul><li>定义两个整数变量<code>a</code>和<code>b</code>，用于存储从JSON中提取的值。</li></ul><hr><h4 id="3-检查串口数据"><strong>3. 检查串口数据</strong></h4><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">if</span> (Serial.<span class="built_in">available</span>() &gt; <span class="number">0</span>) &#123;</span><br><span class="line">  String input = Serial.<span class="built_in">readStringUntil</span>(<span class="string">&#x27;\n&#x27;</span>);</span><br><span class="line">  input.<span class="built_in">trim</span>();</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><ul><li><code>Serial.available()</code>：检查串口是否有数据可读。</li><li><code>Serial.readStringUntil('\n')</code>：读取串口数据，直到遇到换行符<code>\n</code>。</li><li><code>input.trim()</code>：去除输入字符串中的多余空格或换行符。</li></ul><hr><h4 id="4-解析JSON数据"><strong>4. 解析JSON数据</strong></h4><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">StaticJsonDocument&lt;<span class="number">200</span>&gt; doc;</span><br><span class="line">DeserializationError error = <span class="built_in">deserializeJson</span>(doc, input);</span><br></pre></td></tr></table></figure><ul><li><code>StaticJsonDocument&lt;200&gt;</code>：分配200字节的固定大小缓冲区，用于存储JSON数据。</li><li><code>deserializeJson(doc, input)</code>：解析输入的JSON字符串。</li></ul><hr><h4 id="5-检查解析结果"><strong>5. 检查解析结果</strong></h4><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">if</span> (error) &#123;</span><br><span class="line">  Serial.<span class="built_in">print</span>(<span class="string">&quot;解析错误: &quot;</span>);</span><br><span class="line">  Serial.<span class="built_in">println</span>(error.<span class="built_in">c_str</span>());</span><br><span class="line">  <span class="keyword">return</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><ul><li>如果解析失败，<code>deserializeJson</code>会返回一个错误对象。通过<code>error.c_str()</code>可以获取错误信息。</li></ul><hr><h4 id="6-提取参数"><strong>6. 提取参数</strong></h4><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">if</span> (doc.<span class="built_in">containsKey</span>(<span class="string">&quot;a&quot;</span>) &amp;&amp; doc.<span class="built_in">containsKey</span>(<span class="string">&quot;b&quot;</span>)) &#123;</span><br><span class="line">  a = doc[<span class="string">&quot;a&quot;</span>];</span><br><span class="line">  b = doc[<span class="string">&quot;b&quot;</span>];</span><br><span class="line">  Serial.<span class="built_in">print</span>(<span class="string">&quot;成功解析: a = &quot;</span>);</span><br><span class="line">  Serial.<span class="built_in">print</span>(a);</span><br><span class="line">  Serial.<span class="built_in">print</span>(<span class="string">&quot;, b = &quot;</span>);</span><br><span class="line">  Serial.<span class="built_in">println</span>(b);</span><br><span class="line">&#125; <span class="keyword">else</span> &#123;</span><br><span class="line">  Serial.<span class="built_in">println</span>(<span class="string">&quot;JSON中缺少参数a或b&quot;</span>);</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><ul><li><code>doc.containsKey(&quot;a&quot;)</code>：检查JSON对象中是否包含键<code>&quot;a&quot;</code>。</li><li><code>doc[&quot;a&quot;]</code>：提取键<code>&quot;a&quot;</code>对应的值。</li><li>如果JSON中缺少<code>&quot;a&quot;</code>或<code>&quot;b&quot;</code>，则输出错误信息。</li></ul><hr><h3 id="运行示例"><strong>运行示例</strong></h3><h4 id="输入"><strong>输入</strong></h4><p>通过串口监视器发送以下JSON数据：</p><figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">&#123;</span><span class="attr">&quot;a&quot;</span><span class="punctuation">:</span><span class="number">10</span><span class="punctuation">,</span><span class="attr">&quot;b&quot;</span><span class="punctuation">:</span><span class="number">20</span><span class="punctuation">&#125;</span></span><br></pre></td></tr></table></figure><h4 id="输出"><strong>输出</strong></h4><p>串口监视器将显示：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">成功解析: a = 10, b = 20</span><br></pre></td></tr></table></figure><hr><h3 id="注意事项"><strong>注意事项</strong></h3><ol><li><p><strong>JSON格式</strong></p><ul><li>输入的JSON数据必须是有效的JSON格式。例如，键和值需要用双引号包裹，键值对之间用逗号分隔。</li><li>示例：<figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">&#123;</span><span class="attr">&quot;a&quot;</span><span class="punctuation">:</span><span class="number">10</span><span class="punctuation">,</span><span class="attr">&quot;b&quot;</span><span class="punctuation">:</span><span class="number">20</span><span class="punctuation">&#125;</span></span><br></pre></td></tr></table></figure></li></ul></li><li><p><strong>内存分配</strong></p><ul><li><code>StaticJsonDocument&lt;200&gt;</code>的大小需要根据JSON数据的复杂度调整。如果JSON数据较大，可以增加缓冲区大小，例如<code>StaticJsonDocument&lt;512&gt;</code>。</li></ul></li><li><p><strong>错误处理</strong></p><ul><li>如果输入的JSON格式不正确，程序会输出解析错误信息。</li><li>如果JSON中缺少<code>&quot;a&quot;</code>或<code>&quot;b&quot;</code>，程序会提示缺少参数。</li></ul></li><li><p><strong>串口监视器设置</strong></p><ul><li>确保串口监视器的波特率与代码中的<code>Serial.begin(9600)</code>一致。</li><li>在发送JSON数据时，确保末尾包含换行符<code>\n</code>。</li></ul></li></ol><hr><h3 id="扩展功能"><strong>扩展功能</strong></h3><ol><li><p><strong>支持浮点数</strong></p><ul><li>如果<code>a</code>和<code>b</code>是浮点数，可以将变量类型改为<code>float</code>：<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="type">float</span> a = <span class="number">0.0</span>;</span><br><span class="line"><span class="type">float</span> b = <span class="number">0.0</span>;</span><br></pre></td></tr></table></figure></li></ul></li><li><p><strong>动态JSON文档</strong></p><ul><li>如果JSON数据大小不确定，可以使用<code>DynamicJsonDocument</code>：<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="function">DynamicJsonDocument <span class="title">doc</span><span class="params">(<span class="number">200</span>)</span></span>; <span class="comment">// 动态分配200字节的缓冲区</span></span><br></pre></td></tr></table></figure></li></ul></li><li><p><strong>处理嵌套JSON</strong></p><ul><li>如果JSON数据包含嵌套结构，例如：<figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">&#123;</span><span class="attr">&quot;data&quot;</span><span class="punctuation">:</span><span class="punctuation">&#123;</span><span class="attr">&quot;a&quot;</span><span class="punctuation">:</span><span class="number">10</span><span class="punctuation">,</span><span class="attr">&quot;b&quot;</span><span class="punctuation">:</span><span class="number">20</span><span class="punctuation">&#125;</span><span class="punctuation">&#125;</span></span><br></pre></td></tr></table></figure>可以通过以下方式提取：<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">a = doc[<span class="string">&quot;data&quot;</span>][<span class="string">&quot;a&quot;</span>];</span><br><span class="line">b = doc[<span class="string">&quot;data&quot;</span>][<span class="string">&quot;b&quot;</span>];</span><br></pre></td></tr></table></figure></li></ul></li></ol><hr><p>希望这个示例对您有帮助！如果有任何问题，请随时提问。</p>]]></content>
    
    
      
      
    <summary type="html">&lt;blockquote&gt;
&lt;p&gt;&lt;strong&gt;声明&lt;/strong&gt;：此文章由 AI 生成，内容不保证正确。&lt;/p&gt;
&lt;/blockquote&gt;
&lt;h1&gt;使用ArduinoJson库的完整指南&lt;/h1&gt;
&lt;p&gt;&lt;code&gt;ArduinoJson&lt;/code&gt;是一个功能强大且高效</summary>
      
    
    
    
    
    <category term="Arduino" scheme="http://example.com/tags/Arduino/"/>
    
    <category term="技术分享" scheme="http://example.com/tags/%E6%8A%80%E6%9C%AF%E5%88%86%E4%BA%AB/"/>
    
  </entry>
  
  <entry>
    <title>python虚拟环境基础应用</title>
    <link href="http://example.com/post/66526c4.html"/>
    <id>http://example.com/post/66526c4.html</id>
    <published>2025-01-28T03:59:00.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h3 id="查看conda版本">查看conda版本</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">conda --version</span><br></pre></td></tr></table></figure>]]></content>
    
    
      
      
    <summary type="html">&lt;h3 id=&quot;查看conda版本&quot;&gt;查看conda版本&lt;/h3&gt;
&lt;figure class=&quot;highlight plaintext&quot;&gt;&lt;table&gt;&lt;tr&gt;&lt;td class=&quot;gutter&quot;&gt;&lt;pre&gt;&lt;span class=&quot;line&quot;&gt;1&lt;/span&gt;&lt;br&gt;&lt;/pr</summary>
      
    
    
    
    
    <category term="技术" scheme="http://example.com/tags/%E6%8A%80%E6%9C%AF/"/>
    
  </entry>
  
  <entry>
    <title>机器人驱动与运动控制</title>
    <link href="http://example.com/post/1bfd48ce.html"/>
    <id>http://example.com/post/1bfd48ce.html</id>
    <published>2024-12-22T07:05:00.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>简答题</h1><h3 id="1-什么是机器人三原则？">1. 什么是机器人三原则？</h3><p>第一条：机器人不能伤害人类。也不能眼见人类受到伤害而袖手旁观。<br>第二条：机器人应服从人类的命令，但不能违反第一条原则。<br>第三条：机器人应保护自身的安全，但不能违反第一条和第二条原则。<br>这三条原则目前已成为机器人研究人员与研制厂家共同遵守的指导方针。</p><h3 id="2-三相笼型异步电动机的变速方法有哪几种？其各自的适用范畴如何？、">2. 三相笼型异步电动机的变速方法有哪几种？其各自的适用范畴如何？、</h3><p>三相笼型异步电动机可通过以下三种方法进行调速，即改变转差率的变转差率调速、改变极对数的变极调速和改变电动机电源频率的变频调速。<br>变转差率调速方法的调速范围较小，局限性大，应用较少。<br>变极调速方法是通过改变电动机定子绕组的磁极对数进行调速。变极调速属于有级调速，调速平滑度差，一般多用于金属切削机床，如铣床、镗床、磨床等。<br>变频调速方法是利用变频器，改变施加在电动机上的电源频率进行调速。变频调速的调速范围大，调速的稳定性、平滑性均属优良，机械特性较硬。变频调速属于无级调速，适用于绝大部分三相笼型异步电动机。</p><h3 id="3-简述绕线式异步电动机的启动特点及方法？">3. 简述绕线式异步电动机的启动特点及方法？</h3><p>鼠笼式异步电动机多为降压启动，因此启动转矩小，启动电流大，因此不能满足某些生产机械需要高启动转矩低启动电流的要求。绕线式异步电动机由于能在转子电路中串电阻，因此具有较大的启动转矩和较小的启动电流，即具有较好的启动特性。在转子电路中串电阻的启动方法常用的有两种：逐级切除启动电阻法和频敏变阻器启动法。</p><h3 id="4-直流电动机调速方法中，典型的改变电枢电路外串电阻调速方式有哪些缺点？">4. 直流电动机调速方法中，典型的改变电枢电路外串电阻调速方式有哪些缺点？</h3><p>1）机械特性较软，电阻愈大则特性愈软，稳定度愈低；<br>2）在空载或轻载时，调速范围不大；<br>3）实现无级调速困难；<br>4）在调速电阻上消耗大量电能。</p><h3 id="5-简述三相异步交流电动机的变频调速方法及特点？">5. 简述三相异步交流电动机的变频调速方法及特点？</h3><p>三相异步交流电动机变频调速是一种通过改变定子绕组供电频率来改变转子转速的调速方式。由于同步转速与定子频率成正比，改变定子绕组供电频率便可实现转子转速的平滑调节，并且可以获得较宽的调速范围和足够硬的机械特性。因而，在各种方法中，变频调速是一种高性能的调速方案。</p><h3 id="6-电传动系统运动方程中的静态转矩和动态转矩的概念。">6. 电传动系统运动方程中的静态转矩和动态转矩的概念。</h3><p>静态转矩：电动机轴上的负载转矩 TL，它不随系统加速或减速而变化。<br>动态转矩：系统加速或减速时，存在一个动态转矩 Td，它使系统的运动状态发生变化。</p><h3 id="7-例说明机器人的主要分类方式">7. 例说明机器人的主要分类方式</h3><p>按发展时期分类：第一代—示教再现型机器人；第二代—有感觉的机器人；第三代—具有智能的机器人。<br>按几何结构分类：直角坐标机器人；圆柱坐标机器人；球坐标机器；关节型标机器人。<br>按控制方式分类：非伺服控制机器人和伺服控制机器人；其中伺服控制机器人又可划分为：点位伺服控制机器人和连续轨迹伺服控制机器人。<br>按驱动方式分类：电力驱动；液压驱动；气压驱动；新型驱动。</p><h3 id="8-三相笼型异步电动机减压起动的方法有哪几种？">8. 三相笼型异步电动机减压起动的方法有哪几种？</h3><p>三相笼型异步电动机常结构用的减压起动方法有：定子串电阻（或电抗器）减压起动、 星形—三角形（Y/Δ）转换减压起动、自耦变压器减压起动、延边三角形减压起动、软起动器减压起动和变频器减压起动等。</p><h3 id="9-机器人驱动用电动机按照结构形式可分为哪几类？">9. 机器人驱动用电动机按照结构形式可分为哪几类？</h3><p>可根据工作环境的具体条件选择电动机的结构型式，具体可分为以下 4 类。<br>（1）防护式电动机（IP23）能防止大量灰尘和异物进入电机工作区域，避免影响电机正常运行工作。<br>（2）封闭式电动机（IP44）适用于多尘、潮湿、易受风雨侵蚀，有腐蚀性气体等较恶劣的工作环境。<br>（3）密封式电动机（IP68）的密封程度高，外部的气体和液体都不能进入电动机内部，可以浸在液体中使用，潜水泵电动机就是典型的密封式电动机。<br>（4）防爆式电动机<br>防爆式电动机不但有严密的封闭结构，外壳又有足够的机械强度，适用于有易燃、易爆气体的场所，如矿井、油库和煤气站等场所。</p><h3 id="9-电气控制线路中，既装设熔断器，又装设热继电器，各起什么作用？能否相互代用？">9. 电气控制线路中，既装设熔断器，又装设热继电器，各起什么作用？能否相互代用？</h3><p>二者不能相互替换，热继电器和熔断器在电路中的保护作用是不相同的。热继电器只做长期的过载保护，而熔断器是做严重过载和短路保护，因此一个较完整的保护电路，特别是电动机控制电路，应该两种保护都具有。</p><h3 id="10-为什么电动机要设零电压和欠电压保护？">10. 为什么电动机要设零电压和欠电压保护？</h3><p>零电压保护的目的是防止电气设备意外失电后因来电而导致电动机意外自行启动。设置了零电压保护环节，则电气设备意外失电再上电后，必须通过再次启动，电动机才能运行。欠电压保护的目的是防止当电源电压降低时而导致电动机产生故障。当电源电压下降到电动机额定电压的 80％以下后，将导致电动机因转矩不足而转速下降，以致被迫停转，使电动机因堵转而烧毁。</p><h3 id="11-为确保电动机正常工作，在电气控制系统中，需要对电动机采取哪些保护措施？">11. 为确保电动机正常工作，在电气控制系统中，需要对电动机采取哪些保护措施？</h3><p>在电气控制系统中常用的保护环节有短路保护、过载保护、过电流保护、零电压保护、欠电压保护和弱磁保护等。</p><h3 id="12-从结构特征上如何区分交流、直流电磁机构？">12. 从结构特征上如何区分交流、直流电磁机构？</h3><p>交流接触器的线圈通以交流电，将产生涡流和磁滞损耗，使铁心发热。为减少铁损，铁心用硅钢片冲压而成。为便于散热，线圈做成短而粗的筒状绕在骨架上。<br>直流接触器的线圈通以直流电，铁心中不会产生涡流和磁滞损耗，所以不会发热。为方便加工，铁心用整块钢块制成。为使线圈散热良好，通常将线圈绕制成长而薄的筒状。</p><h3 id="13-简述直流电动机制动与自然停车的区别和特点？">13. 简述直流电动机制动与自然停车的区别和特点？</h3><p>1）自然停车：电动机脱离电网，靠很小的摩擦阻转矩消耗机械能使转速慢慢下降，直到转速为零而停车。<br>特点：停车过程需时较长，不能满足生产机械快速停车的要求；<br>2）制动：电动机脱离电网，外加阻力转矩使电动机速度迅速下降，直到转速为零而停车。<br>特点：加快停车过程，提高生产效率；实现准确停车等。</p><h3 id="14-热继电器在电路中的作用是什么？带断相保护和不带断相保护的三相式热继电器各用在什么场合？">14. 热继电器在电路中的作用是什么？带断相保护和不带断相保护的三相式热继电器各用在什么场合？</h3><p>热继电器（FR）主要用于电力拖动系统中电动机负载的过载保护。热继电器的选择主要根据电动机定子绕组的联结方式来确定热继电器的型号，在三相异步电动机电路中，对 Y 连接的电动机可选两相或三相结构的热继电器，一般采用两相结构的热继电器，即在两相主电路中串接热元件。对于三相感应电动机，定子绕组为 A 连接的电动机，必须采用带断相保护的热继电器。</p><h3 id="15-什么是主令电器？常用的主令电器有哪些？">15. 什么是主令电器？常用的主令电器有哪些？</h3><p>主令电器是在自动控制系统中发出指令或信号的电器，用来控制接触器、继电器或其他电器线圈，使电路接通或分断，从而达到控制生产机械的目的。主令电器应用广泛、种类繁多。按其作用可分为：按钮、行程开关、接近开关、万能转换开关、主令控制器及其他主令电器（如脚踏开关、钮子开关、急停开关）等。</p><h3 id="16-自锁环节怎样组成？它起什么作用？并具有什么功能？">16. 自锁环节怎样组成？它起什么作用？并具有什么功能？</h3><p>答：在连续控制中，将接触器的常开辅助触头 KMX 与自复位启动按钮 SBX 并联，即可形成自锁环节。当启动按钮SBX 松开后，接触器 KMX 的线圈通过其辅助常开触头的闭合仍继续保持通电，从而保证电动机的连续运行。这种依靠接触器自身辅助常开触头而使线圈保持通电的控制方式，称自锁或自保。起到自锁作用的辅助常开触头称自锁触头。所以自锁环节的功能就是在启动按钮松开后，能够保待接触器线圈一直通电，使电动机连续运行。</p><h3 id="17-直流电动机工作原理中按定子励磁绕组的励磁方式可分为哪几类？并画出对应的电路图？">17. 直流电动机工作原理中按定子励磁绕组的励磁方式可分为哪几类？并画出对应的电路图？</h3><p>直流电动机也按定子励磁绕组的励磁方式可分他励式，串励式，并励式和复励式四种类型，对应的电路图如下：<br><img src="https://pic.imgdb.cn/item/675a89c4d0e0a243d4e2a986.png" alt="Alt text"></p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;简答题&lt;/h1&gt;
&lt;h3 id=&quot;1-什么是机器人三原则？&quot;&gt;1. 什么是机器人三原则？&lt;/h3&gt;
&lt;p&gt;第一条：机器人不能伤害人类。也不能眼见人类受到伤害而袖手旁观。&lt;br&gt;
第二条：机器人应服从人类的命令，但不能违反第一条原则。&lt;br&gt;
第三条：机器人应保护自身的安全</summary>
      
    
    
    
    
    <category term="期末复习" scheme="http://example.com/tags/%E6%9C%9F%E6%9C%AB%E5%A4%8D%E4%B9%A0/"/>
    
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  <entry>
    <title>单片机期末复习</title>
    <link href="http://example.com/post/f8c2b703.html"/>
    <id>http://example.com/post/f8c2b703.html</id>
    <published>2024-12-02T12:59:00.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h1>1.MOV寻址</h1><ul><li>立即寻址 <code>MOV A, #05H</code>直接赋值05H</li><li>直接寻址 <code>MOV A, 20H</code>赋值地址20H的内容</li><li>寄存器寻址 <code>MOV A, R0</code>特定寄存器R0的内容</li><li>寄存器间接寻址 <code>MOV A, @R0</code>以R0内容为地址</li><li>变址寻址 <code> MOVC A, @A+DPTR</code>A的内容+DPTR的地址</li><li>相对寻址</li><li>位寻址</li><li>MOV操作内部RAM数据</li><li>MOVX操作外部RAM数据</li><li>MOVC操作外部ROM数据</li></ul><hr><h1>定时器</h1><p>8051有<strong>2个</strong>可编程的定时器/计数器，可编程的意思是<strong>指通过写指令设置有关的寄存器</strong>，如工作方式、定时时间、计数初值、启动方式等<br>系统脉冲的12分频作为计数脉冲时用作定时器</p><h2 id="初始化定时器T1">初始化定时器T1</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">MOV TMOD, #10H          ; 确定工作模式</span><br><span class="line">MOV TH1, #高八位初值</span><br><span class="line">MOV TL1, #低八位初值</span><br><span class="line">MOV IE, #88H            ; 开启中断</span><br><span class="line">SETB TR1                ; 启动T0</span><br></pre></td></tr></table></figure><h3 id="TMOD的设置">TMOD的设置</h3><table><thead><tr><th>GATE</th><th>C/T</th><th>M1</th><th>M0</th></tr></thead><tbody><tr><td>0</td><td>定时/计数</td><td>工作方式</td><td>工作方式</td></tr></tbody></table><h3 id="IE的设置">IE的设置</h3><table><thead><tr><th>1000</th><th>T1</th><th>INT1</th><th>T0</th><th>INT0</th></tr></thead></table><table><thead><tr><th>TCON</th><th>TF1</th><th>TR1</th><th>TF0</th><th>TR0</th><th>IE1</th><th>IT1</th><th>IE0</th><th>IT0</th></tr></thead><tbody><tr><td></td><td>T1标志</td><td>T1启停</td><td></td><td>T0启停</td><td></td><td></td><td></td><td></td></tr></tbody></table><ul><li>TR为启停控制位</li></ul><hr><h1>中断</h1><p>中断通常分为<strong>外部中断（INT0，INT1）<strong>和内部中断</strong>（T0，T1）</strong>，还有<strong>串口中断(TI/RI)</strong></p><ol><li><strong>EA</strong>功能：设置 EA（Enable All Interrupts，开全局中断位）。</li><li><strong>EX1 EX0 ET1 ET0</strong>功能：设置指定中断使能位。</li><li><strong>IT0 IT1</strong>功能：置0在<strong>低电平触发</strong>，置1在<strong>负边沿触发</strong>。</li><li>中断源的入口地址</li></ol><table><thead><tr><th>中断</th><th>入口地址</th><th>中断标志位</th></tr></thead><tbody><tr><td>INT0</td><td>0003H</td><td>IE0</td></tr><tr><td>T0</td><td>000BH</td><td>TF0</td></tr><tr><td>INT1</td><td>0013H</td><td>IE1</td></tr><tr><td>T1</td><td>001BH</td><td>TF1</td></tr><tr><td>串口中断</td><td>0023H</td><td>TI/RI</td></tr></tbody></table><ol start="5"><li>中断优先级由中断优先级寄存器<strong>IP</strong> (Interrupt Priority) 控制</li><li>中断服务程序的返回指令必须是RETI</li></ol><hr><ol><li>8051 CPU 数据存储器的寻址能力是<strong>64KB</strong>，范围为<strong>0000~FFFFH</strong></li><li>堆栈寄存器SP有<strong>8位</strong>，特点是用于<strong>标注堆栈的栈顶单元的地址</strong>,复位后内容为<strong>07H</strong>当<strong>执行中断服务程序或调用子程序时</strong>，用<strong>PUSH和POP</strong>指令堆栈保护现场,</li><li><code>INC A</code> 累加器A的值加1<br><code>DEC</code> 累加器A的值减一<br><code>CPL</code> 按位取反<br><code>ANL</code> 按位与(AND)操作<br><code>ORL</code> 按位或(OR)操作<br><code>XRL</code> 按位异或(XOR)操作<br><code>RL</code><br><code>RR</code> 循环右移<br><code>XCH</code> 数据交换指令<br><code>XCHD</code> 交换累加器（A）和目标地址的低四位,只能使用 @R0 或 @R1 指针。<br><code>SWAP</code> 交换高4位和低4位<br><code>MUL AB</code> 无符号乘法，A存低八位，B存高八位<br><code>DIV AB</code> 执行A/B，商存入A，余数存入B</li><li><code>ADD A, 30H</code> A=A+(30H的值)<br><code>ADDC  A， @R0</code> A=A+(@R0的值)+CY<br><code>SUBB</code> 相减</li><li>数据指针寄存器DPTR占用<strong>2个</strong>单元，共有<strong>16位</strong>分别为<strong>DPH</strong> 和<strong>DPL</strong>，都是8位寄存器。用于<strong>作为RAM的指针</strong>，<strong>用来存放片内ROM或片外ROM/RAM地址</strong>。数据位数多意味着存储空间大。</li><li>DA指令为二进制转十进制指令，用于数据显示环节。当计算结果为A~F时，会自动转换至0~9，确保显示正确</li><li>8051单片机有<strong>4个</strong>并行I/O口，<strong>32根</strong>I/O线，P0作<strong>为数据总线和低8位地址总线</strong>，P2口的其他功能为<strong>单片机有外部拓展时，作为高8位地址线使用</strong></li><li>8051控制线RST用于<strong>复位</strong>，分为<strong>上电复位</strong>和<strong>开关复位</strong></li><li>数码管动态显示原理：<strong>接4个数码管的共阳极公共端，比如第一个数码管显示8，只需要通过P1口输出8的字形码，接第一个数码管公共端的P2.0输出高电平即可实现显示8。</strong></li><li>在MCS-51系统中，决定程序执行顺序的寄存器是<strong>PC</strong>，<strong>用来存放下一条将要执行指令的地址</strong>，，<strong>能自动+1</strong>，能存放<strong>16位</strong>二进制数，可<strong>通过转移控制指令修改它的内容</strong></li><li>SJMP是短跳转指令,程序的跳转范围在256字节以内.SJMP LOOP 是相对寻址，开始执行标号为LOOP的指令行。</li><li>8051的最小系统的组成是 <strong>电源电路、单片机、晶振电路、复位电路</strong>。</li><li>PSW寄存器中</li></ol><ul><li>P位是奇偶标志，也就是判断累加器A中1的个数的奇偶。</li><li>F0是用户标志，也就是供程序员使用的位。比如：该位=1，表示电机启动，=0表示电机停止</li></ul><ol start="14"><li>LED数码管有<strong>静态显示</strong>和<strong>动态显示</strong>，静态显示只适用于显示位数较少的场合。动态显示适合显示位数较多场合。</li><li>单片机的特点有<strong>高性能、低价格，体积小、可靠性高，低电压、低功耗</strong>。</li><li>8051 控制线ALE作用是<strong>锁存低8位地址</strong>，8051在访问片外存储器时，P0口输出低8位地址的同时还在ALE线上输出一个高电平脉冲，其下降沿用于把这个片外存储器低8位地址锁存到外部地址锁存器，以便使P0口引脚线传送随后而来的片外存储器读写数据。在不访问片外存储器时，8051CPU自动在ALE/线上输出频率为fosc/6的脉冲序列。</li><li>8051有8个工作寄存器R0 ~ R7，0组：00H~07H; 1组：08H~0FH; 2组：10H~17H; 3组：18H~1FH。</li><li>时钟周期为<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>T</mi><mtext>时钟周期</mtext></msub><mo>=</mo><mn>1</mn><mi mathvariant="normal">/</mi><mtext>晶振频率</mtext></mrow><annotation encoding="application/x-tex">T_{时钟周期}=1/晶振频率</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">T</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3283em;"><span style="top:-2.55em;margin-left:-0.1389em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord cjk_fallback mtight">时钟周期</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">1/</span><span class="mord cjk_fallback">晶振频率</span></span></span></span>，机器周期通常<span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>12</mn><msub><mi>T</mi><mtext>时钟周期</mtext></msub></mrow><annotation encoding="application/x-tex">12T_{时钟周期}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8333em;vertical-align:-0.15em;"></span><span class="mord">12</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.13889em;">T</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.3283em;"><span style="top:-2.55em;margin-left:-0.1389em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord cjk_fallback mtight">时钟周期</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span>，大多数指令周期需要 1～2 个机器周期。</li><li>DAC0832连接方式有<strong>直通方式、单缓冲方式、双缓冲方式</strong>。</li><li>PSEN作用：片外ROM选通控制线</li><li>RD和WR的作用：访问外部RAM读写控制线</li><li>8255工作模式有模式0、1、2；模式0为基本输入输出，模式1为选通输入输出，模式2只有A口能设定。</li><li>8051片内RAM容量是<strong>128B</strong>，可分为<strong>寄存器区，位寻址区，通用RAM区</strong></li><li>A/D 转换芯片ADC0809 中既可做为查询的状态标志,又可作为中断请求信号使用的是EOC，输出允许信号为OE，ADC0809有8个通道</li><li>单片机复位后，PC的值为<strong>0000H</strong>，4个I/O口的值为<strong>FFH</strong>。</li><li>输入接口电路是<strong>指将外部信号送入单片机系统的通道称为 输入接口电路</strong>。<br>输入接口电路作用：<strong>是CPU与外部输入设备进行数据传输的通道，是单片机系统与外部设备交换信息的桥梁</strong>。</li><li>8051最小系统工作方式为<strong>复位方式、程序执行方式、节电方式、EPROM编程和效验方式</strong>。</li><li>8051的内部结构由8个部件组成：<strong>中央处理器(CPU)、片内数据存储器(RAM)、片内程序存储器(ROM/EPROM)、输入输出接口(并行I/O口)、可编程串行口、定时器/计数器、中断系统及特殊功能寄存器。</strong></li><li>计算机中数的表示形式有<strong>无符号数和符号数</strong>，其中符号数有<strong>原码 反码 补码</strong></li><li>单片机时序是指单片机执行指令时应发出的控制信号的时间序列。时钟周期，机器周期，指令周期</li></ol><hr><h1>编程题</h1><h2 id="跳转指令">跳转指令</h2><ul><li><strong>DJNZ</strong> 表示 “Decrement and Jump if Not Zero”（减 1 并跳转，如果不为 0）。</li><li><strong>JNZ</strong>表示 “Jump if Not Zero”（如果<strong>累加器A</strong>值不为零，则跳转）。</li><li><strong>JB</strong> 表示&quot;Jump if Bit is set&quot;（如果位为 1 则跳转）</li><li><strong>JNB</strong>表示&quot;Jump if Bit is not set&quot;（如果位为 0 则跳转）。</li><li><strong>CJNE</strong> 全称为 Compare and Jump if Not Equal（比较并跳转，如果不相等）<br><code>CJNE &lt;source&gt;, &lt;direct&gt;, &lt;label&gt;</code></li></ul><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">比较 &lt;source&gt; 和 &lt;direct&gt; 的值：</span><br><span class="line">如果它们 不相等，程序跳转到 &lt;label&gt;。</span><br><span class="line">如果它们 相等，程序继续执行下一条指令。</span><br><span class="line">更新 进位标志位（C）：</span><br><span class="line">如果 &lt;source&gt; 小于 &lt;direct&gt;，设置 C = 1。</span><br><span class="line">如果 &lt;source&gt; 大于等于 &lt;direct&gt;，清除 C = 0。</span><br></pre></td></tr></table></figure><h3 id="1-用汇编语言编写：统计内部RAM-30H开始的100个数中0的个数并存放在R5中。">1. 用汇编语言编写：统计内部RAM 30H开始的100个数中0的个数并存放在R5中。</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line">    MOV R0, #30H        ;从30H开始</span><br><span class="line">    MOV R5, #0          ；用于储存结果</span><br><span class="line">    MOV R2, 100         ；作为计数器</span><br><span class="line"></span><br><span class="line">LOOP: </span><br><span class="line">    MOV A @R0           ；将统计的内容传到A</span><br><span class="line">    CJNE A, #0 NEXT     ；如果A为0，不跳转，A为1，跳到NEXT</span><br><span class="line">    INC R5              ；若为1，结果加1</span><br><span class="line"></span><br><span class="line">NEXT:</span><br><span class="line">    INC R0              ；加1，指向下一个数</span><br><span class="line">    DJNZ R2, LOOP       ；先减1判断是否为0，不为零跳转</span><br><span class="line"></span><br><span class="line">    SJMP$               ；最后无限循环</span><br><span class="line"></span><br></pre></td></tr></table></figure><h3 id="2-用汇编语言编写：设X和Y均为16位无符号二进制数，分别存放在内部RAM的40H、41H和50H、51H单元，试编写能完成Z-X-Y操作的程序，并且把结果Z送到内部RAM的40H、41H单元。">2. 用汇编语言编写：设X和Y均为16位无符号二进制数，分别存放在内部RAM的40H、41H和50H、51H单元，试编写能完成Z=X+Y操作的程序，并且把结果Z送到内部RAM的40H、41H单元。</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">MOV R0, 40H         ; X的低四位</span><br><span class="line">MOV R1, 50H         ；Y的低四位</span><br><span class="line">MOV A, @R0          ；将X低四位存到A</span><br><span class="line">ADD A, @R1          ；A与Y的低四位相加</span><br><span class="line">MOV @R0, A          ；存入结果</span><br><span class="line">INC R0              ；变高四位</span><br><span class="line">INC R1</span><br><span class="line">MOV A, @R0</span><br><span class="line">ADDC A, @R1         ；计算高四位加低四位的进位</span><br><span class="line">MOV @R0, A</span><br></pre></td></tr></table></figure><h3 id="3-用汇编语言编写：已知系统时钟频率为12MHz，编写延时2s子程序。">3. 用汇编语言编写：已知系统时钟频率为12MHz，编写延时2s子程序。</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line">    MOV R4, #20</span><br><span class="line">DEL2:</span><br><span class="line">    MOV R5, #200</span><br><span class="line">DEL1:</span><br><span class="line">    MOV R6, #250</span><br><span class="line">    DJNZ R6, $          ; 循环R6到0</span><br><span class="line">    DJNZ R5, DEL1       ；R5递减，回到DEL1</span><br><span class="line">    DJNZ R4, DEL2       ；R4递减，回到DEL2</span><br><span class="line">    RET                 ；R4到0时回到主程序</span><br></pre></td></tr></table></figure><h3 id="4-用汇编语言编写：将外部RAM-2000H单元开始的数据块传送到内部RAM-60H开始的位置，直到片外RAM单元出现零为止。">4. 用汇编语言编写：将外部RAM 2000H单元开始的数据块传送到内部RAM 60H开始的位置，直到片外RAM单元出现零为止。</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">    MOV DPTR, #2000H</span><br><span class="line">    MOV R0, 60H</span><br><span class="line">LOOP:</span><br><span class="line">    MOVX A, @DPTR</span><br><span class="line">    MOV R0, @A</span><br><span class="line">    INC DPTR</span><br><span class="line">    INC R0</span><br><span class="line">    JNZ LOOP            ; A不为零跳转</span><br><span class="line">    SJMP $</span><br><span class="line"></span><br></pre></td></tr></table></figure><h3 id="5-用汇编语言编写：统计内部RAM-70H开始的50个单元中负数的个数并存放在R5中。">5. 用汇编语言编写：统计内部RAM 70H开始的50个单元中负数的个数并存放在R5中。</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line">    MOV R1, #70H        ; </span><br><span class="line">    MOV R5, #0          ; 计数负数的个数</span><br><span class="line">    MOV R2, #50         ；计数50个单元</span><br><span class="line">LOOP:</span><br><span class="line">    MOV A, @R1          </span><br><span class="line">    JNB ACC.7 NEXT      ；A的最高位为1不跳转</span><br><span class="line">    INC R5              ；负数加1</span><br><span class="line">MEXT:</span><br><span class="line">    INC R1              ；下一个地址</span><br><span class="line">    DJNZ R2, LOOP       ； 倒数到0跳出</span><br><span class="line">    SJMP $</span><br><span class="line">    </span><br></pre></td></tr></table></figure><h3 id="6-设单片机的晶振频率为6MHz，利用定时器T0的功能，编写能延时10ms的程序。">6. 设单片机的晶振频率为6MHz，利用定时器T0的功能，编写能延时10ms的程序。</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br></pre></td><td class="code"><pre><span class="line">    ORG 00H</span><br><span class="line">    SJMP MAIN</span><br><span class="line"></span><br><span class="line">    ORG 000BH</span><br><span class="line">    SET F0</span><br><span class="line">    RETI</span><br><span class="line">MAIN:</span><br><span class="line">    NOP</span><br><span class="line">    MOV TMOD #01H</span><br><span class="line">    MOV TH0 #ECH</span><br><span class="line">    MOV TL0 #78H</span><br><span class="line">    SETB ET0</span><br><span class="line">    SETB EA</span><br><span class="line">    SETB TR0</span><br><span class="line">    SJMP $</span><br><span class="line"></span><br><span class="line">    END</span><br></pre></td></tr></table></figure><h3 id="7-用汇编语言编写：设内部RAM-地址是20H的单元无符号数X，编写程序实现：求函数Y-9X-21，并把Y送入22H单元，并给出注释。">7. 用汇编语言编写：设内部RAM 地址是20H的单元无符号数X，编写程序实现：求函数Y= 9X +21，并把Y送入22H单元，并给出注释。</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">MOV A, 20H          ; X传入A</span><br><span class="line">MOV B, #9           ；系数传入B</span><br><span class="line">MUL AB              ；AB相乘，低四位存入A</span><br><span class="line">ADD A, #21          ；A加21</span><br><span class="line">MOV 22H,A           ；结果存入</span><br><span class="line">END</span><br><span class="line"></span><br></pre></td></tr></table></figure><h3 id="8-在采用8255扩展I-O口时，若把8255-的PC7引脚作为输入，接一个开关，PB7引脚接一个发光二极管。请编写程序实现以下功能：C口开关接高电平信号时，B口所接的发光二极管点亮。">8. 在采用8255扩展I/O口时，若把8255 的PC7引脚作为输入，接一个开关，PB7引脚接一个发光二极管。请编写程序实现以下功能：C口开关接高电平信号时，B口所接的发光二极管点亮。</h3><p>设8255的地址为X, X+1, X+2, X+3</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">MOV DPTR #X+3       ；控制口地址</span><br><span class="line">MOV A, #89H         ；初始化</span><br><span class="line">MOVX @DPTR, A       ；写入初始化</span><br><span class="line"></span><br><span class="line">MOV DPTR, #X+2      ；转到C口</span><br><span class="line">MOVX A, @DPTR       ；读C口到A</span><br><span class="line"></span><br><span class="line">MOV DPTR #X+1       ；转到B口</span><br><span class="line">MOVX @DPTR, A       ；写入B口</span><br><span class="line"></span><br></pre></td></tr></table></figure><h3 id="9-P2口接8个LED灯，试用汇编编写实现单个LED灯左移程序，延时程序略">9. P2口接8个LED灯，试用汇编编写实现单个LED灯左移程序，延时程序略</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">    MOV A, #FEH         ; 01111111</span><br><span class="line">LOOP:</span><br><span class="line">    MOV P2, A           ; </span><br><span class="line">    ACALL DELAY         ; 暂时跳转到DELAY</span><br><span class="line">    RL A                ；循环左移</span><br><span class="line">    SJMP LOOP</span><br></pre></td></tr></table></figure><h3 id="10-设8051单片机的时钟频率为12MHz，试编写利用定时器T0在P2-0引脚输出周期为1s方波的程序。">10. 设8051单片机的时钟频率为12MHz，试编写利用定时器T0在P2.0引脚输出周期为1s方波的程序。</h3><p>TC=216-T定时/T计数=65536-50ms/1us=15536=3CB0H<br>开T0： #82H     11110010H<br>开T1： #88H     11111000H</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br></pre></td><td class="code"><pre><span class="line">    ORG 000H</span><br><span class="line">    AJMP START</span><br><span class="line"></span><br><span class="line">    ORG 000BH</span><br><span class="line">    AJMP INTT0</span><br><span class="line"></span><br><span class="line">    ORG 0100H</span><br><span class="line">START:</span><br><span class="line">    MOV R2, #10</span><br><span class="line">    MOV TMOD, #01H</span><br><span class="line">    MOV TH0, #3CH</span><br><span class="line">    MOV TL0, #B0H</span><br><span class="line">    MOV IE, #82H</span><br><span class="line">    SETB TR0</span><br><span class="line">    SJMP $</span><br><span class="line"></span><br><span class="line">INTT0:</span><br><span class="line">    DJNZ R2, NEXT</span><br><span class="line">    CPL P2.0</span><br><span class="line">    MOV R2, #10</span><br><span class="line">NEXT: </span><br><span class="line">    MOV TH0, #3CH</span><br><span class="line">    MOV TL0, #B0H</span><br><span class="line">    RETI</span><br><span class="line">    END</span><br><span class="line"></span><br></pre></td></tr></table></figure><hr><h1>方案设计题</h1><h2 id="1-计一种基于89C51单片机的显示工具，以显示范围从000到999的数字。根据本课程所学内容设计一个可行方案，尽量包括方案分析、硬件设计、软件设计等方面，以满足该需求。">1. 计一种基于89C51单片机的显示工具，以显示范围从000到999的数字。根据本课程所学内容设计一个可行方案，尽量包括方案分析、硬件设计、软件设计等方面，以满足该需求。</h2><p>设计一种基于89C51单片机的显示工具，以显示范围从000到999的数字，需要构建一个包含单片机、数码管显示模块以及必要的外围电路的系统。</p><p>以下是详细的设计步骤和要点：</p><p>一硬件设计</p><p>单片机：AT89C51</p><p>数码管：三位共阳或共阴数码管</p><p>驱动电路：如果数码管为共阳，则单片机输出低电平点亮相应段；如果为共阴，则输出高电平点亮。</p><p>电阻和电容：用于限流和去耦</p><p>显示原理:</p><p>使用三个独立的数码管分别显示百位、十位和个位。</p><p>单片机通过控制每个数码管的段选和位选信号来显示不同的数字。</p><p>数码管连接:</p><p>段选：单片机的某个端口（如P0口）连接数码管的段选端，通过输出不同的编码来显示不同的数字。</p><p>位选：使用单片机的另外几个端口（如P2.0, P2.1, P2.2）分别控制三个数码管的位选信号，每次只点亮一个数码管以进行显示。</p><p>电路设计:</p><p>限流电阻：在段选和位选线上串联限流电阻，以防止电流过大损坏数码管或单片机。</p><p>三、 软件设计</p><p>初始化:</p><p>设置单片机的IO口为输出模式。</p><p>初始化定时器（如果需要动态扫描显示）。</p><p>数码管编码</p><p>定义一个包含0-9数字对应的段选编码的数组。</p><p>显示逻辑</p><p>通过读取一个计数器或外部输入的值，将其分解为百位、十位和个位。</p><p>依次点亮每个数码管，并通过段选线输出对应的数字编码。</p><p>使用延时函数确保每个数码管有足够的显示时间。</p><h2 id="2-某部门需要设计一种基于89C51单片机的6位阿拉伯数字密码输入工具。根据本课程所学内容设计一个可行方案，尽量包括方案分析、硬件设计、软件设计等方面，以满足该需求。">2. 某部门需要设计一种基于89C51单片机的6位阿拉伯数字密码输入工具。根据本课程所学内容设计一个可行方案，尽量包括方案分析、硬件设计、软件设计等方面，以满足该需求。</h2><p>设计一种基于89C51单片机的6位阿拉伯数字密码输入工具，主要涉及到硬件电路设计和软件编程两个方面。</p><p>一、硬件设计</p><p>单片机选择：89C51单片机作为核心控制器。</p><p>输入设备：</p><p>键盘：可以采用矩阵键盘或独立按键键盘。考虑到6位数字输入，建议使用6个独立按键，每个按键代表一个数字（0-9，可能需要两个按键组合来表示10，或者通过逻辑判断来区分输入）。如果需要更紧凑的设计，可以使用4x4矩阵键盘，通过软件编码来区分不同的数字输入。</p><p>显示设备（可选）：</p><p>LED灯：简单应用中，可以用LED灯来显示输入状态或密码验证结果。</p><p>二、软件设计</p><p>初始化：</p><p>初始化单片机，包括IO口配置、LCD显示屏（如果使用）的初始化等。</p><p>键盘扫描：</p><p>编写键盘扫描程序，不断检测按键是否被按下。</p><p>如果检测到按键按下，则根据按键的编码确定输入的数字。</p><p>密码输入逻辑：</p><p>定义一个变量或数组来存储输入的密码。</p><p>每当一个数字被输入时，更新密码变量或数组，并显示当前输入的密码（如果使用了显示屏）。</p><p>如果输入超过6位数字，则忽略额外的输入或提示用户重新输入。</p><p>密码验证（可选）：</p><p>在密码输入完成后，可以设计密码验证逻辑。</p><p>将输入的密码与预设的密码进行比较。</p><p>如果密码正确，则执行相应的操作（如解锁设备、点亮LED等）。</p><p>如果密码错误，则给出错误提示，并允许用户重新输入。</p><p>主循环：</p><p>不断重复键盘扫描和密码输入/验证的逻辑，直到满足特定的退出条件（如正确输入密码、达到最大尝试次数等）。</p><h2 id="3-设计一个基于AT89C51单片机的定时工具定时范围10-50秒。请根据本课程所学内容设计一个可行方案，尽量包括方案分析、硬件设计、软件设计等方面，以满足该需求。">3. 设计一个基于AT89C51单片机的定时工具定时范围10~50秒。请根据本课程所学内容设计一个可行方案，尽量包括方案分析、硬件设计、软件设计等方面，以满足该需求。</h2><p>在设计一个基于AT89C51单片机的定时工具时，需要考虑到定时器/计数器的配置、按键输入控制、以及显示输出等多个方面。</p><p>以下是一个设计方案，其定时范围设定为10秒到50秒。</p><p>一、设计分析</p><p>定时范围：10秒至50秒，步长为1秒。</p><p>按键控制：至少需要一个按键来启动和停止定时器，并可能需要调整定时时长。</p><p>显示输出：通过数码管或LCD显示屏显示当前时间或剩余时间。</p><p>二、硬件设计</p><p>单片机：AT89C51</p><p>显示模块：4位数码管（如果采用LCD显示，则可以使用LCD1602）</p><p>按键模块：至少一个按键（可以使用矩阵键盘以支持更多功能，如设置时间等）</p><p>复位电路：用于单片机复位</p><p>三、软件设计</p><p>定时器初始化：</p><p>配置定时器0或定时器1（通常选择定时器0，因为它在AT89C51中更常用）。</p><p>设置定时器的工作模式（通常为模式1，16位定时器/计数器模式）。</p><p>根据晶振频率计算定时器初始值，以实现大约1秒的定时中断。</p><p>按键扫描与处理：</p><p>设计按键扫描程序，用于检测按键是否被按下。</p><p>根据按键的不同功能（如启动、停止、设置时间等），执行相应的处理逻辑。</p><p>时间显示：</p><p>设计显示程序，用于在数码管或LCD上显示当前时间或剩余时间。</p><p>更新显示内容需要在定时器中断服务程序中进行。</p><p>主程序流程：</p><p>初始化单片机、定时器、显示模块等。</p><p>进入主循环，等待按键事件。</p><p>当检测到按键事件时，根据按键功能执行相应操作。</p><p>在定时器中断服务程序中更新显示内容，并处理定时逻辑。</p><h3 id="4-某工厂需要设计一个使用89C51单片机进行开关量的边沿信号检测。请根据本课程所学内容设计一个可行方案，尽量包括方案分析、硬件设计、软件设计等方面，以满足该需求。">4. 某工厂需要设计一个使用89C51单片机进行开关量的边沿信号检测。请根据本课程所学内容设计一个可行方案，尽量包括方案分析、硬件设计、软件设计等方面，以满足该需求。</h3><ol><li>硬件设计</li></ol><p>所需材料：89C51单片机、开关（按钮或限位开关）、电阻（限流用）、电源（适配89C51）、跳线若干、面包板或PCB板</p><p>连接方式：</p><p>将开关的一端连接到89C51的某个外部中断引脚（如INT0或INT1），另一端连接到地。</p><p>开关的另一端通过一个限流电阻连接到单片机的VCC。</p><ol start="2"><li>软件设计</li></ol><p>初始化：</p><p>设置外部中断为边沿触发模式（上升沿或下降沿，根据需求选择）。</p><p>初始化定时器（如果需要进一步的时间控制或测量）。</p><p>初始化串口（如果需要调试信息输出）。</p><p>外部中断服务程序（ISR）：</p><p>编写中断服务程序以响应外部中断。</p><p>在中断服务程序中，首先判断是哪种边沿触发了中断（如果配置为边沿触发，则通常需要软件判断）。</p><p>记录边沿事件（例如，通过翻转一个标志位或增加计数器）。</p><p>如果需要，可以发送中断事件的信息到串口或其他输出设备。</p>]]></content>
    
    
      
      
    <summary type="html">&lt;h1&gt;1.MOV寻址&lt;/h1&gt;
&lt;ul&gt;
&lt;li&gt;立即寻址 &lt;code&gt;MOV A, #05H&lt;/code&gt;直接赋值05H&lt;/li&gt;
&lt;li&gt;直接寻址 &lt;code&gt;MOV A, 20H&lt;/code&gt;赋值地址20H的内容&lt;/li&gt;
&lt;li&gt;寄存器寻址 &lt;code&gt;MOV A, R</summary>
      
    
    
    
    
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  <entry>
    <title>液压期末简答题</title>
    <link href="http://example.com/post/930fa050.html"/>
    <id>http://example.com/post/930fa050.html</id>
    <published>2024-12-02T12:55:00.000Z</published>
    <updated>2025-07-07T23:51:51.358Z</updated>
    
    <content type="html"><![CDATA[<h3 id="1-简述齿轮泵的泄油情况？-减小泄油的主要措施是什么？">1. 简述齿轮泵的泄油情况？ 减小泄油的主要措施是什么？</h3><p>内泄露：齿轮端面与端盖配合处最大（约75%）；<br>齿轮顶部与泵体配合的径向间隙处次之（约15%）；<br>两齿轮的啮合线处最小（约10%）；<br>减小泄漏的主要措施是考虑减小齿轮端面与端盖的配合处泄漏，增加密封，减小间隙等。</p><h3 id="2-简述溢流阀的最主要（最基本）的作用和结构特点？">2. 简述溢流阀的最主要（最基本）的作用和结构特点？</h3><p>最主要的作用是溢流稳压（稳定压力和提供安全保护）<br>(1)控制阀口 控制油液来自进油口。<br>(2)阀口常闭 只有当进油压力达到其调定压力时，阀口才开启，保持进口压力恒定。<br>(3)先导式溢流阀控制油液泄回回油腔。<br>(4)先导式溢流阀外控口外接远程控制阀时。要低于本阀调压。</p><h3 id="3-简述常用液压油有哪几种？最主要特点？说出液压油粘性常用哪三种表示？">3. 简述常用液压油有哪几种？最主要特点？说出液压油粘性常用哪三种表示？</h3><p>种类：石油型、乳化型、合成型<br>石油型主要成分是机械油，耐低温不耐高温，润滑性较好，但通常不抗燃。<br>后两者可归为难燃液压油，主要成分是水，抗燃但不耐低温。<br>液压粘度分：动力粘度、运动粘度和相对粘度三种。</p><h3 id="4-简述平衡回路原理">4. 简述平衡回路原理</h3><p>(1)利用背压抵消液压缸移动部件的部分或全部重量。<br>(2)目的是平衡物体和执行原件重量或防止物体和执行元件由于重量作用而产生自动下行超速现象。<br>(3)平衡回路一般用于在液压缸竖直安放的情况。</p><h3 id="5-什么是卸荷回路，通常有哪两种方式？">5. 什么是卸荷回路，通常有哪两种方式？</h3><p>液压系统中，执行元件短时间停止工作时，不频繁启动液压泵的原动机，使泵在很小的输出功率下运作的回路<br>方式：压力卸荷和流量卸荷</p><h3 id="6-什么是液压基本回路？-常见的液压基本回路有几类？">6. 什么是液压基本回路？ 常见的液压基本回路有几类？</h3><p>由液压元件和辅件组成，能完成某特定功能的典型的、最基本的回路称为液压基本回路<br>压力控制回路 速度控制回路 方向控制回路 多缸控制回路</p><h3 id="7-齿轮泵的液压径向力不平衡是怎样产生的？会带来什么样的后果">7. 齿轮泵的液压径向力不平衡是怎样产生的？会带来什么样的后果?</h3><p>产生原因：一是液体压力产生的径向力，二是困油现象产生的径向力致使泵的径向力不平衡加剧。<br>泵由于径向力不平衡，把齿轮压向吸油的一侧，使齿轮轴受到弯曲作用，影响使用寿命，同时使吸油腔齿轮径向间隙减小，从而使齿轮和泵体产生摩擦或卡死，影响正常工作。</p><h3 id="8-举例说明液压系统的组成">8. 举例说明液压系统的组成</h3><p>动力元件——泵<br>执行元件——液压缸<br>控制元件——流量阀 溢流阀 节流阀<br>辅助元件——油箱 液压油</p><h3 id="9-说出常用的快速回路（增速回路）">9. 说出常用的快速回路（增速回路）</h3><ol><li>差动连接：使双作用单活塞液压缸与二位换向阀实现</li><li>双泵供油回路：由两个泵和外空阀实现</li><li>增速缸增速</li><li>蓄能器增速</li><li>自动充油增速</li></ol><h3 id="10-进油，回油节流调速回路的不同之处">10. 进油，回油节流调速回路的不同之处</h3><ol><li>回油有一定的背压，故液压缸能承受负值负载，且运动速度平稳。进油容易实现压力控制。<br>工作部件运动碰到死挡铁之后，液压缸油腔压力上升至溢流阀调定压力，压力继电器发出信号，可控制下一步操作。</li><li>回油中，油液经节流阀发热后回油箱冷却，对系统泄露影响小。<br>在组成元件相同的条件下，进油在同样的低速时节流阀不易堵塞。</li><li>回油回路的回油腔压力较高，特别是负载接近0时，压力更高，这对回油管的安全、密封、及寿命均有影响。</li></ol>]]></content>
    
    
      
      
    <summary type="html">&lt;h3 id=&quot;1-简述齿轮泵的泄油情况？-减小泄油的主要措施是什么？&quot;&gt;1. 简述齿轮泵的泄油情况？ 减小泄油的主要措施是什么？&lt;/h3&gt;
&lt;p&gt;内泄露：齿轮端面与端盖配合处最大（约75%）；&lt;br&gt;
齿轮顶部与泵体配合的径向间隙处次之（约15%）；&lt;br&gt;
两齿轮的啮合线处最</summary>
      
    
    
    
    
    <category term="期末复习" scheme="http://example.com/tags/%E6%9C%9F%E6%9C%AB%E5%A4%8D%E4%B9%A0/"/>
    
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