November 7, 2012Verifying Trig Identities

Homework questions

HW 5.2: Pg. 387 #4-36, multiples of 4

Use factoring to simplifyExample 3: common factor

difference of squaresa) sin2x csc2x – sin2x b) sec4x –

tan4x

Use these strategies for HW #45-53 odd

Lesson 5.2 Verifying Trig Identities

Goal: Get one side of the equation equal to the other.

Strategy: - Work on one side to make it equal to the other side.

Great first step strategies!

1. Start with the side that seems more complicated: (fractions, common multiples, etc.)

2. Combine fractions – get a common denominator.3. Substitute an identity before multiplying.4. Convert everything to sine and cosine. 5. Write as separate fractions. 6. Work with both sides separately. (Do not

add/subtract/mult/divide to both sides. 7. Factor

Strategy 1. Start with the side that seems more complicated: (fractions, common multiples, etc.

Strategy 2. Combine fractions – get a common denominator.

Strategy 3. Multiplying (tan2x + 1)(cos2x – 1) = -tan2x

Strategy 4. Converting to Sines and Cosines