设函数y=sin(x^2-1),则dy=
问题描述：
设函数y=sin(x^2-1),则dy=
答
y=f(u)=sinu
u=x^2-1
所以dy=f'(u)*u'dx=cosu*2xdx=2xcos(x^2-1)dx
答
2xcos(x^2-1)dx
答
dy=
cos(x^2-1)(x^2-1)'dx
=cos(x^2-1)*2xdx
=2xcos(x^2-1)dx