Question

How do you find the exact value of the sine, cosine, and tangent of the number 2pie/3, without using a calculator?

Answer 1

Find the exact values of 6 trig functions of (2pi)/3

Explanation:

The Table of trig Values of Special Arcs, found in any trig book, gives these values.
sin (2pi)/3 = sqrt3/2
cos (2pi)/3 = -1/2
tan (2pi)/3 = - sqrt3.
from these values you can deduct other trig functions values.