Honors Pre-Calculus Name: __________________________

Unit 6 Day 2 Section 5.4 Double Angle and Half Angle

Find the exact value of the function:

1. If sin $ = &' , 0 < $ < ,- find the exact value of:

a) sin 2$

b) cos 1-

2. If cos $ = − 34 , 5 < $ < &,- find the exact value of:

a) cos 2$

b) sin 1-

Double-angle Formulas:

Half-angle Formulas:

Evaluate each expression:

3. cos 22.5° 4. tan &,;

5. tan −15° 6. sin(− ,>-)

Solve the following equation for @ ≤ B < CD:

7. cos 2$ = cos $ 8. sin $ = cos 2$

9. 2 cos- 1- = 1 10. cos 2$ − cos $ = 2

Verify the identity:

11. 2 sin- 2$ + cos 4$ = 1 12. (GHI$ + JKG$)- = 1 + GHI2$