(1)将a，b两点坐标代入解析式得a+b+c=0，9a+3b+c=0解得b=-4a，c=3a∴y=ax²-4ax+3a∴m(2，-a)(2)将m点坐标代入解析式得3×2+2=-a∴a=-8∴y=-8x²+32x-24
