(i)[3]
Write $f(x)$ in the form $a(x + b)^2 + c$, where $a$, $b$ and $c$ are constants.
(ii)[1]
State the range for $f$.
(iii)[1]
State the domain for $f^{-1}$.
(iv)[4]
On the same diagram, sketch the graphs of $y = f(x)$, $y = g(x)$ and $y = f^{-1}(x)$, showing clearly how the graphs are related.
(v)[3]
Find a formula for $f^{-1}(x)$.