复合函数求导数,分清楚内层函数与外层函数,设外层函数为u外层函数对u求导数,乘以内层函数对x求导,然后把u还回去。
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如果是三层,最外层设为u,中间层设为v,外层对u求导数,乘以中间层对v乘以内层对x求导数。以此类推。主要方法:先对该函数进行分解,分解成简单函数,然后对各个简单函数求导,最后将求导后的结果相乘,并将中间变量还原为对应的自变量。函数相乘求导公式:(fg)=fg+fg,式中两个连续函数f,g及其导数f′,g′则它们的积。乘积法则也称莱布尼兹法则,是数学中关于两个函数的积的导数的一个计算法则。
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