Show that the equation
2sin2x=7cosx+5 2\sin^2 x = 7\cos x + 5 2sin2x=7cosx+5can be written in the form
2cos2x+7cosx+3=0 2\cos^2 x + 7\cos x + 3 = 0 2cos2x+7cosx+3=0Hence solve, for 0≤x<360∘0 \leq x < 360^\circ0≤x<360∘, the equation
2sin2x=7cosx+5 2\sin^2 x = 7\cos x + 5 2sin2x=7cosx+541 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.