How do you find the exact value of tan 165?

Answer 1

tan x = sin x / cos x

sin x = x - (x^3/3!) + (x^5/5!) - (x^7/7!) + (x^9/9!) ... to infinity

cos x = 1 - (x^2/2!) + (x^4/4!) - (x^6/6!) + (x^8/8!) .. to infinity

tan 165 degrees = -0.267949192