x/z=F(y/z) ===> z-x∂z/∂x =F'·(-y∂z/∂x),-x∂z/∂y =F'·(z-y∂z/∂y),
===>
∂z/∂x=z/(x-yF'),∂z/∂y= -zF'/(x-yF'),
===>
x(∂z/∂x)+y(∂z/∂y)= xz/(x-yF')-yzF'/(x-yF') = z.能詳細(xì)點(diǎn)么。或者說每個(gè)過程的理據(jù)能給下嗎？。看不懂。x/z=F(y/z)==兩邊分別對(duì)x,y求導(dǎo)數(shù)(等號(hào)兩端的分母約去)==>z-x∂z/∂x =F'·(-y∂z/∂x),-x∂z/∂y =F'·(z-y∂z/∂y),==解出∂z/∂x,∂z/∂y==> ∂z/∂x=z/(x-yF'),∂z/∂y= -zF'/(x-yF'), ==......==> x(∂z/∂x)+y(∂z/∂y)= xz/(x-yF')-yzF'/(x-yF') = z.追問能詳細(xì)點(diǎn)么。或者說每個(gè)過程的理據(jù)能給下嗎？?？床欢?。