Question

How do you use the angle sum and difference identities to simplify sin375?

Answer 1

Use the trig identity: sin (a + b) = sin a.cos b + sin b.cos a

`sin 375 = sin (360 + 15) = sin 360.cos 15 + sin 15. cos 360.`

`Since sin 360 = 0 and cos 360 = 1 -> sin 375 = sin 15 = 0.259`

Another short way:

sin (360 + 15) = sin 15 = 0.259.