Mathematics 9709 · AS & A Level · Trigonometry

Trigonometry — practice question

(i)[3]

Prove that the identity $\sin(x - 30^\circ) + \cos(x - 60^\circ) \equiv (\sqrt{3})\sin x$ is true.

(ii)[6]

Hence solve the equation $\sin(x - 30^\circ) + \cos(x - 60^\circ) = \frac{1}{2}\sec x$, for values of $x$ satisfying $0^\circ < x < 360^\circ$.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Use the correct $\sin(A-B)$ and $\cos(A-B)$ formulae

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