If f(x) = (1 - 3)2 for 2 > 3, then f-1(x) = ?

We have the following function given:
[tex]f(x)=\text{ (x}-3)^2,\text{ x}\ge3[/tex]And we want to find the inverse function. For this case we can do the following procedure:
First we change the x and y values in the function on this way:
[tex]x=\text{ (y}-3)^2[/tex]And now we just need to solve for x . We begin taking square root in both sides of the equation:
[tex]\pm\sqrt{x}\text{ = }\sqrt{(y-3)^2}[/tex]And simplifying we got:
[tex]\pm\sqrt{x}=\text{ y}-3[/tex]And finally solving for y we got:
[tex]y=f^{-1}(x)=\sqrt{x}+3[/tex]And the best option for this case would be the last one.