Prove the identity: (secx−cosx)2≡sec2x−cosec2x+cot2x−sin2x(\sec x - \cos x)^2 \equiv \sec^2x - \operatorname{cosec}^2x + \cot^2x - \sin^2x(secx−cosx)2≡sec2x−cosec2x+cot2x−sin2x
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.