How to simplify a trigonometric expression by factoring

The video tutorial explains the process of factoring expressions, starting with a quadratic example and extending to higher-degree polynomials. It then applies the same principles to trigonometric expressions involving cosines, demonstrating how to simplify them using trigonometric identities. The tutorial emphasizes understanding the underlying concepts of factoring and simplification.

How does the teacher relate factoring to cosine functions?

What is the final expression derived from factoring cosine squared of X - 1?