Mathematics 9709 · AS & A Level · Functions

Functions — practice question

The function $f$ is defined by $f(x) = a + b\cos x$ for $0 \leq x \leq 2\pi$. It is given that $f\left(\tfrac{1}{3}\pi\right) = 5$ and $f(\pi) = 11$.

(i)[3]

Find the values of $a$ and $b$.

(ii)[3]

Find the set of $k$ values for which $f(x) = k$ has no solution.

Worked solution & mark scheme

This 6-mark question has a full step-by-step worked solution and mark scheme.