The displacement ddd of a mechanical oscillator is modeled by the equation
d=0.9cos(1.5t)−4.0sin(1.5t) d = 0.9 \cos(1.5t) - 4.0 \sin(1.5t) d=0.9cos(1.5t)−4.0sin(1.5t)where ddd is measured in millimetres and ttt is time in seconds. To analyze the peak amplitude of the oscillation, the expression is rewritten in the form Rcos(1.5t+α)R \cos(1.5t + \alpha)Rcos(1.5t+α), where R>0R > 0R>0.
Find the value of RRR.
Circle the correct answer from the options below:
3.13.13.1 \qquad 4.054.054.05 \qquad 4.14.14.1 \qquad 4.94.94.9
Practise AQA A Level Maths 1.8 E: Trigonometry with exam-style questions for A Level Maths. 239 questions covering 1.8.1 Trigonometric definitions, rules and radians, 1.8.2 Small angle approximations (A-level only), 1.8.3 Trigonometric functions and exact values, 1.8.4 Reciprocal and inverse trigonometric functions (A-level only), 1.8.5 Trigonometric identities, 1.8.6 Compound and double angle formulae (A-level only), 1.8.7 Solving trigonometric equations, 1.8.8 Proofs with trigonometric identities, and 1.8.9 Trigonometry in context, matched to the AQA A Level Maths (7357) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
