怎么求全微分z=f(x,x/y)

问题描述:

怎么求全微分z=f(x,x/y)

z=f(x,x/y)
∂z/∂x=f1+f2/y
∂z/∂y=-xf2/y^2
dz=[f1+f2/y]dx+[-xf2/y^2]dy