Prove the identity:
2sinx2cosx−secx≡tan2x \frac{2 \sin x}{2 \cos x - \sec x} \equiv \tan 2x 2cosx−secx2sinx≡tan2x137 exam-style questions on Edexcel A Level Maths Trigonometry and Modelling, covering 7.1 Addition Formulae, 7.2 Double Angle Formulae, 7.3 Solving Trigonometric Equations, 7.4 Simplifying a cos x +- b sin x, 7.5 Proving Trigonometric Identities, and 7.6 Modelling with Trigonometric Functions. Each one has a worked solution and a mark scheme showing where the marks go.