Skip to content

Course home

1.5 Trigonometry

1.5 Trigonometry

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209
Question 200

The vertical displacement of a specialized laboratory sensor, VVV, is modelled by the function V(θ)=8cos⁡θ+15sin⁡θV(\theta) = 8\cos \theta + 15\sin \thetaV(θ)=8cosθ+15sinθ, where θ\thetaθ is the phase angle in radians.

a.

Express V(θ)V(\theta)V(θ) in the form Rcos⁡(θ−α)R\cos(\theta - \alpha)Rcos(θ−α), where R>0R > 0R>0 and 0<α<π20 < \alpha < \frac{\pi}{2}0<α<2π​. Give the exact value of RRR and the value of α\alphaα, in radians, to 3 decimal places.

[3]
b.

A secondary performance metric for the sensor, H(t)H(t)H(t), is defined by H(t)=12−3V(4t)H(t) = 12 - 3V(4t)H(t)=12−3V(4t), for t≥0t \ge 0t≥0, where ttt is the time in seconds.

Using the answer to part (a), (i) determine the exact maximum value of H(t)H(t)H(t). (ii) find the smallest positive value of ttt for which this maximum value occurs, giving your answer to 2 decimal places.

[3]
Markscheme

1.5 Trigonometry Questions

  1. A Level
  2. /Maths
  3. /1.5 Trigonometry

317 exam-style questions on OCR A Level Maths 1.5 Trigonometry, covering 1.5.1 Definitions for all arguments, 1.5.2 Sine and cosine rules, 1.5.3 Area of a triangle, 1.5.4 Radian measure (A-level only), 1.5.5 Small angle approximations (A-level only), 1.5.6 Graphs of basic trigonometric functions, 1.5.7 Exact values in radians (A-level only), 1.5.8 Reciprocal and inverse trigonometric ratios (A-level only), 1.5.9 Graphs of reciprocal and inverse functions (A-level only), 1.5.10 Trigonometric identities, 1.5.11 Further trigonometric identities (A-level only), 1.5.12 Double angle and compound angle formulae (A-level only), 1.5.13 Geometrical proofs of formulae (A-level only), 1.5.14 Harmonic form Rcos / Rsin (A-level only), 1.5.15 Trigonometric equations, 1.5.16 Proof involving trigonometric functions (A-level only), and 1.5.17 Trigonometric functions in context. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank