We are given the following function:
We are asked to determine its inverse function:
To do that, we will do the following change:
We get:
Now, since we want to determine the inverse we will swap variables, like this:
Now we will solve for "y", first by squaring both sides:
Now we will add 21 to both sides:
Now we will divide both sides by 7:
This is the inverse function, therefore, we can do the following change:
We get: