Mathematics 9709 · AS & A Level · Trigonometry

Trigonometry — practice question

(main)[5]

Solve the equation $5\cos\theta(1 + \cos 2\theta) = 4$ within $0^\circ \leq \theta \leq 360^\circ$.

Worked solution & mark scheme

This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Use the identity $\cos 2\theta = 2\cos^2\theta - 1$” …

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