关于乘积函数的导函数的一个注记

A Note about the Derivative Function of Product Function

基于求乘积函数的导函数所出现的"漏点"现象,讨论了在不满足求导法则条件时乘积函数的可导性问题,给出了关于此问题的判定定理,并证明了对于二元函数的乘积函数的可微性也有一个有趣的相似结论。

based on the ＇ miss point＇ phenomenon while seeking the derivative function of product function, the derivability of product function is discussed while the function doesn＇t satisfied the conditions of derivation rule, brings out the criterion theorem of this problem, and proved that there is a similar interesting conclusion on the dif- ferentiability of the product function of binary function.