9709 P11 - Jun 2017 - Q5
572
The equation of a curve is \(y = 2 \cos x\).
(i) Sketch the graph of \(y = 2 \cos x\) for \(-\pi \leq x \leq \pi\), stating the coordinates of the point of intersection with the \(y\)-axis.
Points \(P\) and \(Q\) lie on the curve and have \(x\)-coordinates of \(\frac{\pi}{3}\) and \(\pi\) respectively.
(ii) Find the length of \(PQ\) correct to 1 decimal place.
The line through \(P\) and \(Q\) meets the \(x\)-axis at \(H (h, 0)\) and the \(y\)-axis at \(K (0, k)\).
(iii) Show that \(h = \frac{5}{9} \pi\) and find the value of \(k\).
