Verifying Trig Identities with Double Angle Formulas

In this video, I will explain 3 double angle formulas
cos squared u minus sin squared u
2 cos squared u minus 1
1 - 2 sin squared u

This video goes with following Math Standard: Prove and apply trigonometric identities.
Prove addition, subtraction, double and half-angle formulas for sine, cosine, and tangent and use them to solve problems.
Georgia Math Standard, MGSE9-12.F.TF.9

Everything you need to know about Trig Identities Playlist
https://www.youtube.com/playlist?list=PLurjkZV1ykGYVZxjQFw8O2F30yxh-CeD-