Prove the identity: sec2x−cosec2x≡tan2x−cot2x\sec^2x - \operatorname{cosec}^2x \equiv \tan^2x - \cot^2xsec2x−cosec2x≡tan2x−cot2x
Prove the identity: (secx−kcosx)2≡tan2x−k2sin2x+(k−1)2(\sec x - k\cos x)^2 \equiv \tan^2 x - k^2\sin^2 x + (k-1)^2(secx−kcosx)2≡tan2x−k2sin2x+(k−1)2
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.