Prove the identity: sec2x−tan2x≡1\sec^2x - \tan^2x \equiv 1sec2x−tan2x≡1
Prove the identity: (secx+cosx)2≡sec2x+2secxcosx+cos2x(\sec x + \cos x)^2 \equiv \sec^2x + 2\sec x\cos x + \cos^2x(secx+cosx)2≡sec2x+2secxcosx+cos2x
274 exam-style questions on Edexcel A Level Maths Trigonometric Functions, covering 6.1 Secant, Cosecant and Cotangent, 6.2 Graphs of Sec x, Cosec x and Cot x, 6.3 Using Sec x, Cosec x and Cot x, 6.4 Trigonometric Identities, and 6.5 Inverse Trigonometric Functions. Each one has a worked solution and a mark scheme showing where the marks go.