Simple Trig Identities

1 / 10

# Simple Trig Identities - PowerPoint PPT Presentation

Simple Trig Identities. Definition of An Identity. Any equation that is true for every number in the domain of the equation. Example 2x + 12 = 2(x + 6) Trig identities Pythagorean Identities Reciprocal identities Ratio identities. Pythagorean Identities. 90º. (x,y). r. y. θ. 0º.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Simple Trig Identities

Definition of An Identity
• Any equation that is true for every number in the domain of the equation.
• Example
• 2x + 12 = 2(x + 6)
• Trig identities
• Pythagorean Identities
• Reciprocal identities
• Ratio identities
Pythagorean Identities

90º

(x,y)

r

y

θ

• Consider that
• then

180º

x

360º

270º

Ratio Identities
• Since we know that and
Working with Identities
• If you get stuck work on the other side and see if you can make them the same
Example
• Prove
Working with Identities
• Tips
• In an expression, look for a part of the expression that looks like part of one of the identities
• Substitute that in
• Look for factors to cancel
• Look for terms of an expression that can be combined to form one of the identities
• Also possible to look at identities in different forms
Example
• Prove
Example
• Prove