The diagram shows parts of the curves y=2cos2θy = 2\cos^2\thetay=2cos2θ and y=2−sinθy = 2 - \sin\thetay=2−sinθ, where θ \theta\,θ is in degrees.
Show that the equation 2−sinθ=2cos2θ2 - \sin\theta = 2\cos^2\theta2−sinθ=2cos2θ can be expressed in the form 2sin2x−sinx=02\sin^2 x - \sin x = 02sin2x−sinx=0
Solve the inequality 2−sinθ>2cos2θ2 - \sin\theta > 2\cos^2\theta2−sinθ>2cos2θ for 0∘≤θ<360∘0^\circ \leq \theta < 360^\circ0∘≤θ<360∘
322 exam-style questions on Edexcel A Level Maths Trigonometric Identities and Equations, covering 10.1 Angles in all four Quadrants, 10.2 Exact Values of Trigonometric Ratios, 10.3 Trigonometric Identities, 10.4 Solving Trigonometric Equations, 10.5 Harder Trigonometric Equations, and 10.6 Equations and Identities. Each one has a worked solution and a mark scheme showing where the marks go.