一、點(diǎn)關(guān)于已知點(diǎn)或已知直線對(duì)稱(chēng)點(diǎn)問(wèn)題 1、設(shè)點(diǎn)P(x,y)關(guān)于點(diǎn)(a,b)對(duì)稱(chēng)點(diǎn)為P (x ,y ), x =2a-x 由中點(diǎn)坐標(biāo)公式可得:y =2b-y 2、點(diǎn)P(x,y)關(guān)于直線L:Ax+By+C=O的對(duì)稱(chēng)點(diǎn)為 x =x-(Ax+By+C) P (x ,y )則 y =y-(AX+