Mathematics 9709 · AS & A Level · Functions

Functions — practice question

The functions $f$ and $g$ are given by $f: x \mapsto 2 - 3\cos x$ for $0 \leq x \leq 2\pi$, and $g: x \mapsto \frac{1}{2}x$ for $0 \leq x \leq 2\pi$.

(i)[3]

Solve $f g(x) = 1$.

(ii)[3]

Sketch the curve for $y = f(x)$.

Worked solution & mark scheme

This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Valid function $f(x)=2-3\cos(\tfrac12 x)$” …