Question

How would you find the exact values of the six trigonometric functions of the given angle 2pi/3?

Answer 1

locate
\[\frac{2\pi}{3}\] on the unit circle, first coordinate is cosine, second is sine, etc. a good unit circle is here
http://tutorial.math.lamar.edu/cheat_table.aspx
go to last page of trig cheat sheet

Answer 2

your in quadrant 2 so sine is positive! not cos sorry. Use the special triangle and then inverse your ratios, sin=opp/hyp, cos=adj/hyp, tan=opp,adj