Find the exact values of the six trigonometric functions of 165º

Question

Find the exact values of the six trigonometric functions of 165º

I understand how to do this using special triangles but what do you do when the reference angle is something other than 30,45 or 90. I believe the reference angle for this problem is 15

Answer 1

165 = 45 + 120

I think that should do it for you.

For example: sin(45+120) = sin 45 cos 120 +cos 45 sin 120

and sin 45 = cos 45 = (1/2)sqrt(2)

sin 120=sin 60 = 1/2 ...you take it from here.