Question

sinx平方的导数怎么算的[cos(x²)](x²)'怎么得到这一步的

Answer 1

复合函数求导,令u=x^2,则 sin(x^2)=sinu,

d(sinu)/dx= [d(sinu)/du](du/dx) = cosu (du/dx) = cos(x^2)(x^2)'=2xcos(x^2).