Find the exact result for $\int_{\frac{\pi}{4}}^{2\pi} 3 \sin x \cot \frac{1}{2}x \, dx$.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Use one or both of $\sin 2\theta = 2\sin\theta\cos\theta$ and $\cot\theta = \dfrac{\cos\theta}{\sin\theta}$” …