Question

将抛物线y=2x平方-12x+16,绕它的顶点旋转180°,所得抛物线的解析式是 ,为什么.

Answer 1

y = 2x^2-12x+16 = 2(x-3)^2 -2

y+2 = 2(x-3)^2

绕顶点旋转180°,顶点不变,2(x-3)^2前面变号：

y+2 = -2(x-3)^2

y= -2(x-3)^2 -2 = -2x^2+12x-20