## cos(A - B) Formula.jpg - Section 2: Explore

cos(A - B) Formula.jpg

# Does cos(A - B) = cos(A) - cos(B)?

Unit 5: Trigonometric Relationships
Lesson 4 of 15

## Big Idea: Students disprove a potential identity and then derive the real cos(A - B) formula.

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Standards:
Subject(s):
Math, Precalculus and Calculus, Trigonometry, trigonometric functions (Simplifying), trigonemetric identities, sum and difference formulas, Trigonometric Equations
50 minutes

### Tim Marley

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