Question

已知二次函数y=a²+bx+c(a≠0)的图像经过点A(0,6),B(1,0)C(0,3)（1）求出这个二次函

Answer 1

设x = a(y-9/2)^2 +b

1=81a/4 +b

1.5^2 a + b = 0

解,a = 1/18

b = -1/8

x = (y-9/2)^2 / 18 - 1/8

顶点（-1/8,9/2）,对称轴y=9/2