y=-3x²+2x-1化顶点式

问题描述:

y=-3x²+2x-1化顶点式

y=-3x²+2x-1
y=-3(x²-2/3x+1/3)
y=-3(x²-2/3x+1/9-1/9+1/3)
y=-3{(x-1/3)²+2/9}
y=-3(x-1/3)²-2/3