1 / 8

3.8 Fundamental Identities

3.8 Fundamental Identities. –A trig identitiy is a trig equation that is always true –We can prove an identity using the definitions of trig functions (they use x, y, and r). Ex 1) Use definitions to prove:. We also have the Pythagorean Identities. “I tan in a second”.

lila-ford
Download Presentation

3.8 Fundamental Identities

An Image/Link below is provided (as is) to download presentation 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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 3.8 Fundamental Identities

  2. –A trig identitiy is a trig equation that is always true –We can prove an identity using the definitions of trig functions (they use x, y, and r) Ex 1) Use definitions to prove:

  3. We also have the Pythagorean Identities “I tan in a second” (get by ÷ by cos2θ) “I cotan in a cosecond” (get by ÷ by sin2θ)

  4. We can prove identities (using θ, ϕ, β, etc) or verify the identity using specific values. Ex 2) Use exact values to verify the identity for the given θ a) LHS: 60° 1 RHS:

  5. Ex 2) Use exact values to verify the identity for the given θ b) 1 150° 30° LHS: RHS:

  6. Reciprocal: Other Identities to use: Ratio: Pythagorean Identities: (already mentioned) Odd/ Even:

  7. Ex 3) Simplify by writing in terms of sine & cosine a) (try ratio & reciprocal) b)  Pythag (1 + tan2θ = sec2θ)  odd/even 1

  8. Homework #308 Pg 169 #1–45 odd Hints for HW  Make sure calculator is in correct MODE  Draw those reference triangle pictures!

More Related