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Trigonometric Identities and Equations

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Question 104
a.

Show that the equation 1+cos⁡x=3sin⁡2xcos⁡x1 + \cos x = \dfrac{3\sin^2 x}{\cos x}1+cosx=cosx3sin2x​ can be written in the form 4cos⁡2x+cos⁡x−3=04\cos^2 x + \cos x - 3 = 04cos2x+cosx−3=0

[3]
b.

Hence solve, for 0≤x<360∘0 \leq x < 360^\circ0≤x<360∘, the equation, 1+cos⁡x=3sin⁡2xcos⁡x1 + \cos x = \dfrac{3\sin^2 x}{\cos x}1+cosx=cosx3sin2x​. Give your answers to one decimal place where appropriate.

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Markscheme

Trigonometric Identities and Equations Questions

  1. A Level
  2. /Maths
  3. /Trigonometric Identities and Equations

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.

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