Mathematics 9709 · AS & A Level · Functions

Functions — practice question

Functions $f$ and $g$ are given by $f(x)=(x+3)^2-12$ for $x\geq 0$, and $g(x)=2x-5$ for $x\in\mathbb{R}$.

(a)[1]

State the range of $f$.

(b)[2]

Find an expression for $f^{-1}(x)$.

(c)[4]

Solve the equation $gf(x)=69$.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “State $f(x)\ge -3$ or $y\ge -3$” …