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Trigonometry and Modelling

Trigonometry and Modelling

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Question 72
i.

A mechanical sensor measures the angular misalignment α \alpha\,α of a rotating component. The misalignment follows the equilibrium condition:

6sin⁡(α−35∘)=−5cos⁡(α−35∘) 6 \sin(\alpha - 35^\circ) = -5 \cos(\alpha - 35^\circ) 6sin(α−35∘)=−5cos(α−35∘)

Determine all possible values of α \alpha\,α in the range 0<α<360∘0 < \alpha < 360^\circ0<α<360∘, giving your answers to one decimal place.

[4]
ii a.

Show that the equation describing the lateral vibration of a specific piston,

5sin⁡3x=7sin⁡x−4sin⁡xcos⁡x 5 \sin^3 x = 7 \sin x - 4 \sin x \cos x 5sin3x=7sinx−4sinxcosx

can be written in the form

sin⁡x(acos⁡2x+bcos⁡x+c)=0 \sin x (a \cos^2 x + b \cos x + c) = 0 sinx(acos2x+bcosx+c)=0

where aaa, b b\,b and c c\,c are integers to be found.

[3]
ii b.

Hence find all real solutions for −π≤x≤π-\pi \le x \le \pi−π≤x≤π to the equation

5sin⁡3x=7sin⁡x−4sin⁡xcos⁡x 5 \sin^3 x = 7 \sin x - 4 \sin x \cos x 5sin3x=7sinx−4sinxcosx

giving your answers to two decimal places where appropriate.

[3]
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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