Mathematics 9709 · AS & A Level · Trigonometry

Trigonometry — practice question

(i)[4]

Prove the identity $\left(\frac{1}{\sin x} - \frac{1}{\tan x}\right)^2 = \frac{1 - \cos x}{1 + \cos x}$.

(ii)[3]

Hence solve the equation $\left(\frac{1}{\sin x} - \frac{1}{\tan x}\right)^2 = \frac{2}{5}$ for $0 \leq x \leq 2\pi$.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Applies $\tan x=\frac{\sin x}{\cos x}$” …