1. replace f(x) with y:
[tex]\begin{gathered} y=\frac{\sqrt[]{x}}{2} \\ \end{gathered}[/tex]2. Replace every x with a y and replace every y with an x:
[tex]\begin{gathered} x=\frac{\sqrt[]{y}}{2} \\ \end{gathered}[/tex]3. Solve for y:
[tex]y=4x^2=(2x)^2[/tex]4. replace y with f-1(x):
[tex]f^{-1}(x)=(2x)^2[/tex]