Question

Express each of the following as a single trigonometric ratio, and then evaluate

Use double angle formula

a) 2 sin pi over 12 cos Pi over 12
b) 2 sin 45 degree cos 45 degree
c) 2 tan 60 degree cos^2 60 degree

Answer 1

a) 2 sin$(\pi/12)$ cos $(\pi/12)$ =sin $(\pi/6)$=0.5

b) 2 sin 45°cos 45° = sin 90°= 1

c) 2 tan 60°cos² 60° = 2 (sin 60°/cos 60°) cos² 60° = 2 sin 60° cos 60°= sin 120° = $\sqrt{3}/2 = 0.866$