To find the inverse of y=(×-9)^2 replace y with x and x with y and then solve for y.
[tex]y=(x-9)^2[/tex]
[tex]x=(y-9)^2[/tex]
[tex]\pm \sqrt{x} = \sqrt{(y-9)^2}[/tex]
[tex]\pm\sqrt{x} = (y-9)[/tex]
[tex]\pm\sqrt{x} =y-9[/tex]
[tex]\pm\sqrt{x} =y- 9 + 9[/tex]
[tex]9 \pm\sqrt{x} = y[/tex]
[tex]y = 9\pm\sqrt{x}[/tex]
[tex]f(x)^{-1} = 9 \pm\sqrt{x}[/tex]
