The function is given as

To find the inverse of f(x)
Let f(x) = y
This implies

Make x the subject of the equation
First, add 12 to both sides of the equation

This gives

Divide both sides of the equation by 9

Next, take the square root of both sides of the equation
![\begin{gathered} \sqrt[]{(y+12)/(9)}=\sqrt[]{x^2} \\ \Rightarrow x=\sqrt[]{(y+12)/(9)} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/bep5crmvgjueonolj9b1xfclftcrf9cylk.png)
Let the inverse be g(x)
Hence, for the inverse substitute x for y
This gives
![g(x)=\sqrt[]{(x+12)/(9)}](https://img.qammunity.org/2023/formulas/mathematics/college/nzz5g9ha7bdp7rla1ykqjbm8yfzokk4u12.png)