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Trigonometry and Modelling

Trigonometry and Modelling

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Question 10
a.

By writing sin⁡3A \sin 3A\,sin3A as sin⁡(2A+A)\sin(2A + A)sin(2A+A), show that sin⁡3A=3sin⁡A−4sin⁡3A\sin 3A = 3\sin A - 4\sin^3 Asin3A=3sinA−4sin3A.

[2]
b.

Solve, for 0≤A≤1800 \leq A \leq 1800≤A≤180, the equation,

3sin⁡A−4sin⁡3A=0.85 3\sin A - 4\sin^3 A = 0.85 3sinA−4sin3A=0.85

Give your answers to 1 decimal place.

[4]
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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