Given that
5cosθ−12sinθ≡Rcos(θ+α) 5 \cos \theta - 12 \sin \theta \equiv R \cos(\theta + \alpha) 5cosθ−12sinθ≡Rcos(θ+α)find the value of RRR, where R>0R > 0R>0.
Circle the correct answer from the options below:
555 \qquad 777 \qquad 131313 \qquad 171717
221 exam-style questions on CCEA A Level Maths 3.4 Trigonometry (A-level only), covering 3.4.1 Trigonometry (A-level only), 3.4.2 Trigonometry (A-level only), 3.4.3 Trigonometry (A-level only), 3.4.4 Trigonometry (A-level only), 3.4.5 Trigonometry (A-level only), 3.4.6 Trigonometry (A-level only), 3.4.7 Trigonometry (A-level only), and 3.4.8 Trigonometry (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.