设函数z=sin(y/x)+e-xy,求∂2z/∂y2.
z=sin(y/x)+e(-xy) ∴∂z/∂y=(1/x)cos(y/x)+(-x)e(-xy) ∴∂2z/∂y2=-(1/x2)sin(y/x)+(-x)2e-xy=-(1/x2) sin(y/x)+x2e-xy.
设函数z=sin(y/x)+e-xy,求∂2z/∂y2.
z=sin(y/x)+e(-xy) ∴∂z/∂y=(1/x)cos(y/x)+(-x)e(-xy) ∴∂2z/∂y2=-(1/x2)sin(y/x)+(-x)2e-xy=-(1/x2) sin(y/x)+x2e-xy.