Mathematics 9709 · AS & A Level · Trigonometry

Trigonometry — practice question

(a(i))[3]

Write $(\sqrt{3})\cos x + \sin x$ as $R \cos(x - \alpha)$, with $R > 0$ and $0 < \alpha < \tfrac{1}{2}\pi$, and state the exact values of $R$ and $\alpha$.

(a(ii))[4]

Thus show that $\displaystyle \int_{\pi/6}^{\pi/2} \frac{1}{((\sqrt{3})\cos x + \sin x)^2} \, dx = \tfrac{1}{4}\sqrt{3}$.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: State that $R=2$

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI