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Trigonometry and Modelling

Trigonometry and Modelling

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Question 97
a.

Show that the equation

2sin⁡θcos⁡θ3sin⁡θ−2=3tan⁡θ,sin⁡θ≠23 \frac{2\sin\theta \cos\theta}{3\sin\theta - 2} = 3\tan\theta, \quad \sin\theta \neq \frac{2}{3} 3sinθ−22sinθcosθ​=3tanθ,sinθ=32​

can be written in the form

2sin⁡3θ+9sin⁡2θ−8sin⁡θ=0 2\sin^3\theta + 9\sin^2\theta - 8\sin\theta = 0 2sin3θ+9sin2θ−8sinθ=0
[4]
b.

Hence solve, for −π2<x<π2-\frac{\pi}{2} < x < \frac{\pi}{2}−2π​<x<2π​

2sin⁡xcos⁡x3sin⁡x−2=3tan⁡x \frac{2\sin x \cos x}{3\sin x - 2} = 3\tan x 3sinx−22sinxcosx​=3tanx

giving your answers to 3 decimal places where appropriate.

[4]
Markscheme

Trigonometry and Modelling Questions

  1. A Level
  2. /Maths
  3. /Trigonometry and Modelling

137 exam-style questions on Edexcel A Level Maths Trigonometry and Modelling, covering 7.1 Addition Formulae, 7.2 Double Angle Formulae, 7.3 Solving Trigonometric Equations, 7.4 Simplifying a cos x +- b sin x, 7.5 Proving Trigonometric Identities, and 7.6 Modelling with Trigonometric Functions. Each one has a worked solution and a mark scheme showing where the marks go.

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