The curve \(C\) has polar equation \(r = 3a \cos \theta\), \(-\frac{\pi}{2} \leq \frac{\pi}{2}\). The curve \(D\) has polar equation \(r = a(1 + \cos \theta)\), \(-\pi \leq \theta < \pi\). Given that \(a\) is a positive constant,
- sketch, on the same diagram, the graphs of \(C\) and \(D\), indicating where each curve cuts the initial line. [4]
The graphs of \(C\) intersect at the pole \(O\) and at the points \(P\) and \(Q\).
- Find the polar coordinates of \(P\) and \(Q\). [3]
- Use integration to find the exact value of the area enclosed by the curve \(D\) and the lines \(\theta = 0\) and \(\theta = \frac{\pi}{3}\). [7]
The region \(R\) contains all points which lie outside \(D\) and inside \(C\).
Given that the value of the smaller area enclosed by the curve \(C\) and the line \(\theta = \frac{\pi}{3}\) is
$$\frac{3a^2}{16}(2\pi - 3\sqrt{3}),$$
- show that the area of \(R\) is \(\pi a^2\). [4]