Sum and Difference Identities for Cosine
Channel: Andrew Misseldine
Date: 2021-05-21

In this video, we state and prove the sum and difference identities for cosine and use them to compute trigonometric values and prove trigonometric identities.

This is lecture 17 (part 1/3) of the lecture series offered by Dr. Andrew Misseldine for the course Math 1060 - Trigonometry at Southern Utah University. A transcript of this lecture can be found at Dr. Misseldine's website or through his Google Drive at: https://drive.google.com/file/d/1a2YqAqgiwi0CabCKYGdT7Q_fcU20f1Ew/view

This lecture is based upon general college trigonometry curriculum and not based upon an individual textbook. With that said, this lecture series is influenced by many great trigonometry textbooks on the market, namely Sullivan's, Stewart's, OpenStax's, McKeague's, Stitz-Zeager's, and many others. Please post any questions you might have below in the comment field and Dr. Misseldine (or other commenters) can answer them for you. Please also subscribe for further updates.