Question

y=sinxy+cos(x+y)求y对x的偏导数

Answer 1

y`=cosxy(y+xy`)-sin(x+y)(1+y`)

=ycosxy+xy`cosxy-sin(x+y) -y`sin(x+y)

y`-xy`cosxy+y`sin(x+y)=ycosxy-sin(x+y)

y`=[ycosxy-sin(x+y)]/[1-xcosxy+sin(x+y)]