Mathematics 9709 · AS & A Level · Functions

Functions — practice question

The diagram presents the graph of $y = f(x)$, where $f$ is defined by $f(x) = 3 + 2\sin\left(\frac{1}{4}x\right)$ for $0 \leq x \leq 2\pi$.
(a)[2]

On the diagram above, sketch $y = f^{-1}(x)$.

(b)[2]

Find a formula for $f^{-1}(x)$.

(c)[2]

The diagram above shows part of the graph of $g(x)=3+2\sin\left(\tfrac{1}{4}x\right)$ for $-2\pi\le x\le 2\pi$. Complete the sketch of $g(x)$ on the diagram above and hence explain whether the function $g$ has an inverse.

(d)[6]

Describe fully a sequence of three transformations that may be combined to change the graph of $y=\sin x$ for $0\le x\le \tfrac{1}{2}\pi$ into the graph of $y=f(x)$, making the order of application clear.

Worked solution & mark scheme

This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: Accurately drawing the line $y=x$

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