Answer
$g(x) = x^{2} - 9$
$f(x) = x^{\frac{1}{3}}$
Work Step by Step
$h(x) = (f$ o $g)(x)$
$= \sqrt[3] {x^{2} - 9}$
$= (x^{2} - 9)^{\frac{1}{3}}$
$= f(g(x))$
$= f(x^{2} - 9)$
$= (x^{2} - 9)^{\frac{1}{3}}$
$g(x) = x^{2} - 9$
$f(x) = x^{\frac{1}{3}}$