In a study of mechanical resonance, an engineer models the response of a vibrating system where the amplitude ratio RRR is determined by an angle of oscillation θ\thetaθ. For sin2θ≠0\sin 2\theta \neq 0sin2θ=0, prove the identity
2cosec 2θ−tanθ=cotθ2\text{cosec } 2\theta - \tan \theta = \cot \theta2cosec 2θ−tanθ=cotθ
Explain why the identity 2cosec 2θ−tanθ=cotθ2\text{cosec } 2\theta - \tan \theta = \cot \theta2cosec 2θ−tanθ=cotθ is not valid for values of θ\thetaθ where sinθ=0\sin \theta = 0sinθ=0.
Practise Edexcel A Level Maths 7.5 Proving Trigonometric Identities with exam-style questions for A Level Maths. 27 questions, matched to the Edexcel A Level Maths (9MA0) 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.