Name: __________________________________________________________ Date: ___________________________
Pre-Calc – HW on All Double Angles (Sine, Cosine, Tangent)
1. Using a double angle identity, show that
sin 300 
 3
.
2
3. Find cos 2 if sin  
1
.
6
For 5-9, find the exact value.
5. 2sin15 cos15
7. 1  2sin 2
2 tan
9.
1  tan

6

8
2

8
2. Using a double angle identity, show that
1
cos 240   .
2
4. Find tan 2 if tan  
4
.
3
6. cos 2 22.5  sin 2 22.5
8. 2sin
10.

8
cos

8
2 tan 60
1  tan 2 60