Question

How do you find the value of `sin120` using the double angle identity?

Answer 1

`sqrt3/2`

Explanation:

Use trig identity: sin 2a = 2sin a.cos a
sin 120 = 2sin 60.cos 60
Trig table -->
sin 60 = 1/2 and cos 60 = sqrt3/2. There for:
`sin 120 = 2 (1/2)(sqrt3/2) = sqrt3/2`