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この動画「高等数学（同济版）视频：9.3 多元函数的全微分及其形式的不变性。详细讲解多元函数的连续性、偏导数及全微分之间的关系，条理清晰，通俗易懂。考研必备的知识点
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详细讲解正项级数敛散性判别法使用策略与技巧（三）。高等数学精讲：正项级数的积分判别法和拉贝判别法，通俗易懂。・
如何将二重积分在直角坐标系中化为累次积分，在什么情况下需要交换积分次序，如何交换？高等数学精讲：直角坐标系中二重积分的计算方法，讲解详细、动画精准、通俗易懂。・
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曲线积分在什么情况下与积分路径无关，理解起来有那么难吗？高等数学精讲：曲线积分与路径无关的条件及其若干应用。讲解详细、通俗易懂。・
全微分和微分是不是一回事儿，服务对象各是什么？全微分、偏导数和连续性有什么关系？高等数学精讲：多元函数的全微分、存在条件及计算方法。讲解详细、通俗易懂。・
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