Mathematics 9709 · AS & A Level · Functions

Functions — practice question

The functions $f$ and $g$ are given by: $f(x) = (x - 2)^2 - 4$ for $x \geq 2$, $g(x) = ax + 2$ for $x \in \mathbb{R}$, with $a$ as a constant.
(a)[1]

State the range for $f$.

(b)[2]

Find the inverse function $f^{-1}(x)$.

(c)[3]

With $a = -\frac{5}{3}$, solve $f(x) = g(x)$.

(d)[5]

If $g\,f^{-1}(12) = 62$ instead, find the possible values of $a$.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: Accept $f(x)\ge -4$ or $[-4,\infty)$

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