1. Section 5.5B Half Angle Formulas
The signs of and depend on the
quadrant in which lies.

2. Ex 6: Find the exact value of sin 105°.
Ex 7: Find the solutions of
in the interval [0, 2π)

3. Product-to-Sum Formulas

4. Ex 8: Rewrite the product as a sum or a difference.

5. Sum-to-Product Formulas

6. Ex 9: Find the exact value of cos 195° + cos 105°.
Ex 10: Find all the solutions of sin 5x + sin 3x = 0
on the interval [0, 2π).

7. Suggested Assignment:
Section 5.5B
pg 382 – 383
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