1. 10.1 – Sine & Cosine Formulas Sum & Difference Formulas

2. Learning Objectives Find exact values of angles NOT on unit circle ▫Use the unit circle to help! Simplify expressions ▫By condensing the sum/difference formulas

3. Cosine Sum and Difference Formulas There are two main purposes for the addition formulas: finding exact values of trigonometric expressions and simplifying expressions to obtain other identities.

4. Example Set 1:Find the Exact Value A.cos(15°) B.sin(7π/12) C.cos(405°)

5. Example Set 2:Simplify the Expression

6. Homework Textbook p. 373 #1-5 odd, 13-19 odd