1.37: Cosine curve intersecting a horizontal line

0606/12/M/J/19 — Question 9 · 9 marks

1.37 diagram
The diagram shows the curve y=4+2cos⁡3xy = 4 + 2\cos 3x intersecting the line y=5y = 5 at the points PP and QQ.
(i)
Find, in terms of π\pi, the xx-coordinate of PP and of QQ.
[3]
(ii)
Find the exact area of the shaded region. You must show all your working.
[6]