The function is f(x) = x^2 - 36. => y = x^2 - 36. To find the inverse function, you can exchange the variables (x,y) and the solve for the new y => x = y^2 - 36 => y^2 = x + 36 => y = +/- sqrt of x + 36. So, the answer is +/- square root of the quantity x plus 36
