sec4A−tan4A≡2sec2A−1\sec^4 A - \tan^4 A \equiv 2\sec^2 A - 1sec4A−tan4A≡2sec2A−1
[2]
b.
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=3
[4]
Markscheme
6.4 Trigonometric Identities Questions
12 exam-style questions on Edexcel A Level Maths 6.4 Trigonometric Identities. Each one has a worked solution and a mark scheme showing where the marks go.