已知y=1/2(x-1)^2+1.且y的算数平方根是3.求x的值.

Question

已知 y=1/2(x-1)^2 +1.且y的算数平方根是3.求x的值.

Answer 1

y=3 ^2=9
1/2(x-1)^2 +1=9
(x-1)^2 =16
x-1=±4
x1=5,x2=-3