∂z/∂x=[1/(1+(xy)²)]*y=y/(1+x²y²)∂z/∂y=[1/(1+(xy)²)]*x=x/(1+x²y²) 求偏导数就像求导数一样，只需把其它变量看成常数即可：Dz/Dx = {1/[1+(xy)²]}*y = y/[1+(xy)²]，D²z/DxDy = D(y/[1+(xy)²])/Dy
