Given that x=120∘x=120^\circx=120∘ is one of the values in the interval 0≤x<360∘0 \leq x < 360^\circ0≤x<360∘, for which 2cos2x−3sin2x=kcosx2\cos^2 x - 3\sin^2 x = k\cos x2cos2x−3sin2x=kcosx, find the value of k k\,k and all the other values for xxx. Give your answers to one decimal place.
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.