抛物线y=-(x+1)(x-3)的顶点坐标是?

问题描述:

抛物线y=-(x+1)(x-3)的顶点坐标是?

y=-(x+1)(x-3)
=-(x²-2x-3)
=-(x²-2x+1-4)
=-(x-1)²+4
顶点坐标是(1,4)