(i)[3]
Solve the equation $f(x) = 7$, and give your answer correct to $2$ decimal places.
(ii)[2]
Sketch the graph for $y = f(x)$.
(iii)[1]
Explain why the function $f$ has an inverse.
(iv)[3]
Obtain an expression for $f^{-1}(x)$.
Mathematics 9709 · AS & A Level · Functions
Functions — practice question
The function $f : x \mapsto 5 + 3\cos\left(\frac{1}{2}x\right)$ is defined over the interval $0 \le x \le 2\pi$.