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Radians

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Question 3
a.

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

3cos⁡(2θ)+cos⁡2(θ)≈4−7θ2+0.25θ4 3 \cos(2\theta) + \cos^2(\theta) \approx 4 - 7\theta^2 + 0.25\theta^4 3cos(2θ)+cos2(θ)≈4−7θ2+0.25θ4
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b.

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

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c.

Calculate the percentage error in your approximation

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Markscheme

Radians Questions

  1. A Level
  2. /Maths
  3. /Radians

69 exam-style questions on Edexcel A Level Maths Radians, covering 5.1 Radian Measure, 5.2 Arc Length, 5.3 Areas of Sectors and Segments, 5.4 Solving Trigonometric Equations, and 5.5 Small Angle Approximations. Each one has a worked solution and a mark scheme showing where the marks go.

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