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3.5 Trigonometry (A-level only)

3.5 Trigonometry (A-level only)

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Question 34
a.

Given that θ \theta\,θ is small, use the small angle approximation of cos⁡θ \cos \theta\,cosθ to show that

4cos⁡(θ)+cos⁡2(2θ)≈5−6θ2+4θ4 4 \cos(\theta) + \cos^2(2\theta) \approx 5 - 6\theta^2 + 4\theta^4 4cos(θ)+cos2(2θ)≈5−6θ2+4θ4
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b.

Hence find an approximation of 4cos⁡(θ)+cos⁡2(2θ)4 \cos(\theta) + \cos^2(2\theta)4cos(θ)+cos2(2θ) when θ=3∘\theta = 3^\circθ=3∘

[2]
c.

Calculate the percentage error in your approximation

[2]
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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