Question

z=x^2sin(xy),对x的偏函数怎么求sin（xy）这块怎么处理?

Answer 1

因为是对x的偏导,把y当成常数

即先积法则

dz/dx=(x^2)'sin(xy)+x^2(sin(xy))'

=2xsin(xy)+x^2cos(xy)*(xy)'

=2xsin(xy)+x^2cos(xy)*y