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Trigonometry

Medium
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Question 6
a.

Show that the equation

4sin⁡2x+9cos⁡x−6=0 4 \sin^2 x + 9 \cos x - 6 = 0 4sin2x+9cosx−6=0

can be written as

4cos⁡2x−9cos⁡x+2=0. 4 \cos^2 x - 9 \cos x + 2 = 0. 4cos2x−9cosx+2=0.
[2]
b.

Hence solve, for 0≤x<720∘0 \leq x < 720^\circ0≤x<720∘,

4sin⁡2x+9cos⁡x−6=0, 4 \sin^2 x + 9 \cos x - 6 = 0, 4sin2x+9cosx−6=0,

giving your answers to 1 decimal place.

[6]
Markscheme

Trigonometry Questions

  1. A Level
  2. /Old Maths
  3. /Trigonometry

10 exam-style questions on Edexcel A Level Old Maths Trigonometry. Each one has a worked solution and a mark scheme showing where the marks go.

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