\(f(x) = x^{2} - 25\) can be written as \(y = x^{2} - 25\)
when finding inverse the first step is to interchange x and y in the equation
∴ \((x) = (y)^{2} - 25\)
then you simply solve for y
\(x + 25 = y^{2}\)
\(y = \sqrt{ (x + 25)}\)
Thus \(f^{-1} (x) = \sqrt{(x + 25)}\)
