Prove the identity: 3sec2x−3cosec2x≡3tan2x−3cot2x3\sec^2x - 3\operatorname{cosec}^2x \equiv 3\tan^2x - 3\cot^2x3sec2x−3cosec2x≡3tan2x−3cot2x
Prove the identity: (secx−3cosx)2≡tan2x−9sin2x+4(\sec x - 3\cos x)^2 \equiv \tan^2 x - 9\sin^2 x + 4(secx−3cosx)2≡tan2x−9sin2x+4
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.