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Trigonometry and Modelling

Trigonometry and Modelling

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Question 1
a.

Show that

cos⁡θ(9tan⁡θ+4tan⁡θ)≡5sin⁡θ+4sin⁡θ \cos \theta \left( 9 \tan \theta + \frac{4}{\tan \theta} \right) \equiv 5 \sin \theta + \frac{4}{\sin \theta} cosθ(9tanθ+tanθ4​)≡5sinθ+sinθ4​

for θ≠nπ2\theta \neq \frac{n\pi}{2}θ=2nπ​, where nnn is an integer.

[3]
b.

Hence solve, for 0<x<2π0 < x < 2\pi0<x<2π, the equation

cos⁡x(9tan⁡x+4tan⁡x)=12sin⁡x−2 \cos x \left( 9 \tan x + \frac{4}{\tan x} \right) = 12 \sin x - 2 cosx(9tanx+tanx4​)=12sinx−2

giving your answers to 3 significant figures.

[5]
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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