Question

z=e^(2x)*sin(x-y),求dz

Answer 1

∂z/∂x=2e^(2x)*sin(x-y)+e^(2x)*cos(x-y)

∂z/∂y=-e^(2x)*cos(x-y)

dz=[2e^(2x)*sin(x-y)+e^(2x)*cos(x-y)]dx-e^(2x)*cos(x-y)dy