Verify Trigonometric Identities Double Angle

The video tutorial reviews Pythagorean identities and demonstrates how to simplify trigonometric expressions. It emphasizes recognizing and using identities to rewrite and simplify expressions, ultimately leading to a final simplification using the cosine of 2X formula.

What is the result of cosine squared of X minus sine squared of X?

Describe how to manipulate the expression to achieve a clean result without arrows or additional complexity.