Use the identity cos2θ+sin2θ=1\cos^2\theta + \sin^2\theta = 1cos2θ+sin2θ=1 to prove that sec2θ=1+tan2θ\sec^2\theta = 1 + \tan^2\thetasec2θ=1+tan2θ.
Solve, for 0≤θ≤2π0 \leq \theta \leq 2\pi0≤θ≤2π, the equation,
sec2θ+3tan2θ=13 \sec^2\theta + 3\tan^2\theta = 13 sec2θ+3tan2θ=13Give your answers in terms of π\piπ.
317 exam-style questions on AQA A Level Maths 1.8 E: Trigonometry, 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. Each one has a worked solution and a mark scheme showing where the marks go.