In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable.
Solve, for 0<x⩽π0 < x \leqslant \pi0<x⩽π, the equation
6sinxtanx+5=2cosx 6 \sin x \tan x + 5 = 2 \cos x 6sinxtanx+5=2cosxgiving your answer in radians to 3 significant figures.
The dissolved oxygen concentration, DDD mg/L, in a fish pond ttt hours after midnight is modelled by the equation
D=15+10sin(kt−35)∘0⩽t<24 D = 15 + 10 \sin(kt - 35)^\circ \quad 0 \leqslant t < 24 D=15+10sin(kt−35)∘0⩽t<24where kkk is a constant. Use the equation of the model to answer parts (a) to (c).
Given that
Find all possible values for kkk, giving each answer to 2 decimal places.
Given further that 0<k<150 < k < 150<k<15
Find the maximum dissolved oxygen concentration in the pond.
Find the time of day at which this maximum concentration occurs. Give your answer to the nearest minute.
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.