Alg2 Sem 2 Unit 7 Lesson 4 Pythagorean Trig Identities - Intro and Derivation

1 of 4 - Now we are going to start adding some new, slightly scarier looking identities to our toolbox. The good news about this, though, is that all of them are derived from one, relatively simple identity - cosine theta squared plus sine squared theta equals one. And it's called a Pythagorean identity because it comes from right triangles formed inside the unit circle. Not only that, but it sure looks a heckuva lot like the good ole Pythagorean Theorem, too. So, don't freak out and give it a sporting chance. I think you'll find it's not too bad at all.