(i)[2]
Find simplified expressions for $fg(x)$ and $gf(x)$.
(ii)[3]
Find the value of $a$ such that $fg(a) = gf(a)$.
(iii)[2]
Find the value of $b$ $(b \neq a)$ satisfying $g(b) = b$.
(iv)[2]
Find a simplified expression for $f^{-1}g(x)$.
(v)[2]
Find an expression for $h^{-1}(x)$, where $h : x \mapsto x^2 - 2$, when $x \leq 0$.