已知拋物線線y=ax2+bx-1經(jīng)過點(3,2).所以有9a+3b-1=23a+b=1y=ax^2+(1-3a)x-1設(shè)P(x,y)是拋物線y=ax^2+(1-3a)x-1關(guān)于y軸對稱的拋物線c2上任意一點P點關(guān)于Y軸對稱點是P1（-x,y) 因為P1在y=ax^2+(1-3a)x-1上所以y=ax^2-(...已知拋物線線y=x2+bx-1經(jīng)過點(3,2).求與這條拋物線關(guān)于y軸對稱的拋物線c2的解析式打錯了，沒a那就取a=1吧y=ax^2-(1-3a)x-1變?yōu)閥=x^2+2x-1