Show that
cosθ(4tanθ+3tanθ)≡sinθ+3sinθ \cos \theta \left( 4 \tan \theta + \frac{3}{\tan \theta} \right) \equiv \sin \theta + \frac{3}{\sin \theta} cosθ(4tanθ+tanθ3)≡sinθ+sinθ3for θ≠nπ2\theta \neq \frac{n\pi}{2}θ=2nπ.
Hence solve, for 0<x<2π0 < x < 2\pi0<x<2π, the equation
cosx(4tanx+3tanx)=6sinx−1 \cos x \left( 4 \tan x + \frac{3}{\tan x} \right) = 6 \sin x - 1 cosx(4tanx+tanx3)=6sinx−1giving your answers to 3 significant figures.
Practise AQA A Level Maths 1.8 E: Trigonometry with exam-style questions for A Level Maths. 239 questions covering 1.8.1 Trigonometric definitions, rules and radians, 1.8.2 Small angle approximations (A-level only), 1.8.3 Trigonometric functions and exact values, 1.8.4 Reciprocal and inverse trigonometric functions (A-level only), 1.8.5 Trigonometric identities, 1.8.6 Compound and double angle formulae (A-level only), 1.8.7 Solving trigonometric equations, 1.8.8 Proofs with trigonometric identities, and 1.8.9 Trigonometry in context, matched to the AQA A Level Maths (7357) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.