9709 P3 - Jun 2005 - Q6 - 8 marks
53
(i) Prove the identity:
\(\cos 4\theta + 4\cos 2\theta \equiv 8\cos^4 \theta - 3\).
(ii) Hence solve the equation:
\(\cos 4\theta + 4\cos 2\theta = 2\),
for \(0^\circ \leq \theta \leq 360^\circ\).
Solutions locked. Please sign in with access to view them.