examday

Community mocks

Clavis TMUA Set B Paper 1 · Q5

Paper 1TrigonometryGeometry

The angle θ\theta satisfies 0<θ<π20<\theta<\frac\pi2 and

sin⁡2θ+sin⁡4θ+sin⁡6θ+sin⁡8θ+⋯=3.\sin^2\theta+\sin^4\theta+\sin^6\theta+\sin^8\theta+\cdots=3.

Find the value of cos⁡θ\cos\theta.

A14\frac14
B13\frac13
C12\frac12
D13\frac1{\sqrt3}
E32\frac{\sqrt3}{2}
F34\frac34

Read the questions freely. Sign in to check your answer, see the worked solution and save your progress.

Sign in to check your answerPractise the whole paper →