Question

Which function below is the inverse of f(x) = x^2 - 16

Answer 1

$f(x) = x^{2} - 16$
$y + 16 = x^{2} - 16 + 16$
$y + 16 = x^{2}$
$\sqrt{y + 16} = \sqrt{x^{2}}$
$\±\sqrt{y + 16} = x$
$\±\sqrt{x + 16} = y$
$\±\sqrt{x + 16} = f^{-1}(x)$