Question

Which function below is the inverse of f(x) = x2 − 36?

Answer 1

Reverse the roles of x and y, then solve for y:
\[x = y ^{2} - 36\]
\[y = +/- \sqrt{x+36}\]

Answer 2

To verify a relationship such as this plot the two functions. You can use free software such as Geogebra, or the Wolfram Alpha website for this purpose.