Prove that:
sec4A−tan4A≡2sec2A−1\sec^4 A - \tan^4 A \equiv 2\sec^2 A - 1sec4A−tan4A≡2sec2A−1
Hence solve, for 0≤A≤3600 \leq A \leq 3600≤A≤360, the equation,
sec4A−tan4A=3 \sec^4 A - \tan^4 A = 3 sec4A−tan4A=3221 exam-style questions on CCEA A Level Maths 3.4 Trigonometry (A-level only), covering 3.4.1 Trigonometry (A-level only), 3.4.2 Trigonometry (A-level only), 3.4.3 Trigonometry (A-level only), 3.4.4 Trigonometry (A-level only), 3.4.5 Trigonometry (A-level only), 3.4.6 Trigonometry (A-level only), 3.4.7 Trigonometry (A-level only), and 3.4.8 Trigonometry (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.