- #1
Joe_K
- 33
- 0
Homework Statement
Find the exact value, without a calculator using half-angle identities, of sin -7pi/8
Homework Equations
Half-angle formula of sin: sin(x/2) = +/- sqrt (1-cosx)/(2)
The Attempt at a Solution
I am confused as to how to use this formula. So far I have:
sin (-7pi/8) = sqrt (1-cos (-7pi/4))/2