1
y=a(x-3)^2-1且图像过(0.7)
9=a(-3)^2-1=9a-1
a=9/10
y=9(x-3)^2/10-1
2.图像过(0.-2)(1,2)且对称轴为直线x=3/2
y=a(x-3/2)^2+c
x=0,y=9a/4+c=-2
x=1,y=a/4+c=2
a=-2
c=5/2
解析式y=-2(x-3/2)^2+5/2