Show that sin2θsinθ−cos2θcosθ≡secθ\frac{\sin 2\theta}{\sin \theta} - \frac{\cos 2\theta}{\cos \theta} \equiv \sec \thetasinθsin2θ−cosθcos2θ≡secθ for θ≠nπ2\theta \neq \frac{n\pi}{2}θ=2nπ where n∈Zn \in \mathbb{Z}n∈Z.
Solve, for 0∘≤x<45∘0^\circ \le x < 45^\circ0∘≤x<45∘, the equation 7cos2(4x−10∘)=37 \cos^2(4x - 10^\circ) = 37cos2(4x−10∘)=3 giving your answers in degrees to one decimal place. (Solutions based entirely on graphical or numerical methods are not acceptable.)
Practise Edexcel A Level Maths Trigonometry and Modelling with exam-style questions for A Level Maths. 100 questions 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, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.