| Exam Board | OCR |
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| Module | C3 (Core Mathematics 3) |
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| Topic | Addition & Double Angle Formulae |
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3. (i) Use the identity for \(\sin ( A + B )\) to show that
$$\sin 3 x \equiv 3 \sin x - 4 \sin ^ { 3 } x$$
(ii) Hence find, in terms of \(\pi\), the solutions of the equation
$$\sin 3 x - \sin x = 0$$
for \(x\) in the interval \(0 \leq x < 2 \pi\).