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3.5 Trigonometry (A-level only)

3.5 Trigonometry (A-level only)

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Question 107
a.

By writing sin⁡3θ \sin 3\theta\,sin3θ as sin⁡(2θ+θ)\sin(2\theta + \theta)sin(2θ+θ), show that

sin⁡3θ≡3sin⁡θ−4sin⁡3θ\sin 3\theta \equiv 3\sin\theta - 4\sin^3\thetasin3θ≡3sinθ−4sin3θ

[2]
b.

Solve, for 0°≤θ≤180°0° \leq \theta \leq 180°0°≤θ≤180°, the equation

3sin⁡θ−4sin⁡3θ=0.43\sin\theta - 4\sin^3\theta = 0.43sinθ−4sin3θ=0.4

Give your answers to one decimal place.

[4]
Markscheme

3.5 Trigonometry (A-level only) Questions

  1. A Level
  2. /Maths
  3. /3.5 Trigonometry (A-level only)

225 exam-style questions on WJEC A Level Maths 3.5 Trigonometry (A-level only), covering 3.5.1 Trigonometry (A-level only), 3.5.2 Trigonometry (A-level only), 3.5.3 Trigonometry (A-level only), 3.5.4 Trigonometry (A-level only), 3.5.5 Trigonometry (A-level only), 3.5.6 Trigonometry (A-level only), 3.5.7 Trigonometry (A-level only), and 3.5.8 Trigonometry (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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