1. Fundamental
Trigonometric Identities
Essential Questions
How do we use fundamental trigonometric identities to simplify and rewrite expressions and to verify other identities?
Holt McDougal Algebra 2
Holt Algebra 2

2. You can use the fundamental trigonometric identities to simplify expressions.
If you get stuck, try converting all of the trigonometric functions to sine and cosine functions.
Helpful Hint

3. Using Trigonometric Identities to Rewrite Trigonometric Expressions
Rewrite each expression in terms of sin θ and cos θ. Then simplify.
1. sec x (1 – sin2x)

4. Using Trigonometric Identities to Rewrite Trigonometric Expressions
Rewrite each expression in terms of sin θ and cos θ. Then simplify.
2. sin x cos x (tan x + cot x)
Distributive property

5. Using Trigonometric Identities to Rewrite Trigonometric Expressions
Rewrite each expression in terms of sin θ and cos θ. Then simplify.
Factor the numerator

6. Using Trigonometric Identities to Rewrite Trigonometric Expressions
Rewrite each expression in terms of sin θ and cos θ. Then simplify.

7. Using Trigonometric Identities to Rewrite Trigonometric Expressions
Rewrite each expression in terms of sin θ and cos θ. Then simplify.

8. Using Trigonometric Identities to Rewrite Trigonometric Expressions
Rewrite each expression in terms of sin θ and cos θ. Then simplify.

9. Lesson 11.3 Practice B