Question

Find f(x) and g(x) so that the function can be described as y=f(g(x)). Y=2/x^2+9

Answer 1

$\bf \begin{cases} f(x)=\cfrac{2}{x}\\[1em] g(x)=x^2+9 \end{cases}~\hspace{5em}f(~~g(x)~~)=\cfrac{2}{g(x)}\implies f(~~g(x)~~)=\cfrac{2}{x^2+9}$

that's one combination for f(x) and g(x), off many combinations.