抛物线y=ax²+bx+c的对称轴是直线x=1,与x轴交于A(-2,0),顶点到x轴的距离为2,求抛物线的表达

设y=a(x-1)²+2或y=a(x-1)²-2
代人点A(-2,0)得9a+2=0或9a-2=0
∴a=2/9或-2/9
∴y=2/9(x-1)²+2或y=-2/9(x-1)²-2