曲線f(x,y)=0關(guān)于直線x-y-2=0對(duì)稱的曲線方程為?
急啊
設(shè)曲線f（x,y)=0關(guān)于直線x-y-2=0對(duì)稱的曲線方程是y=g(x,y)
g(x,y)上有一點(diǎn)(x,y),則此點(diǎn)關(guān)于直線x-y-2=0對(duì)稱的點(diǎn)(x',y')在曲線f（x,y)=0上
有(x+x')/2-(y+y')/2-2=0
(y-y')/(x-x')=-1
解得x'=y+2
y'=x-2
有y=f(y+2,x-2)=g(x,y)
想問(wèn)一下(y-y')/(x-x')=-1這一步是如何解的下一步x,y的值的?