The equation 8cos2x=5−2sinx8\cos^2 x = 5 - 2\sin x8cos2x=5−2sinx can be written in the form 8sin2x−2sinx−3=08\sin^2 x - 2\sin x - 3 = 08sin2x−2sinx−3=0.
Hence solve, for 0≤x<360∘0 \leq x < 360^\circ0≤x<360∘, the equation, 8cos2x=5−2sinx8\cos^2 x = 5 - 2\sin x8cos2x=5−2sinx. Give your answers to one decimal place where appropriate.
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.