To answer this question, the first step we need to do is solve the equation for x. Then, we have:

Then, changing y by x, we finally have that the inverse function is:

To check this result, if we have that x = 1 for the first equation, the value of y is:

If we use this result in the inverse function, then we must have y = 1 ( that is the original value). That is

Therefore, option 3 is the answer.