Find the exact value of each expression below
Key idea:
The sign outside the radical is determined by the half angle
Underneath the radical, use the value for the full angle
Find the exact value of sin 105°
What quadrant is 1/2(210) = 105° in?
What quadrant is 210° in?
Find the exact value of sin 22.5
22.5° in Q__
for sin(45/2)
use _____
use cos 45°
here
Use half angle formulas to find cos 105°
105° not on unit circle, we can use the half angle formula with 210°
13
Find
5
α
12
if α is in Q1