设X^2+Y^2-XY=1,求dy/dx

设X^2+Y^2-XY=1,求dy/dx
设X^2+Y^2-XY=1,求dy/dx

设X^2+Y^2-XY=1,求dy/dx
x^2+y^2-xy=1
求导得：
2x+2yy'-2y-2xy'=0
y'(2y-2x)=2y-2x
y'=1

d(x^2+y^2-xy)=0
2xdx+2ydy-xdy-ydx=0
(2x-y)dx+(2y-x)dy=0
dy/dx=(2x-y)/(x-2y)

2x+2yy'-2y-2xy'=0 y'(2y-2x)=2y-2x y'=1 八字d(x^2+y^2-xy)=0 2xdx+2ydy-xdy-ydx=0 (2x-y)dx+(2y-x)dy=0 dy/dx=(

饿 头大了 好久没做题了