Using sum and difference formulas to verify a trigonometric identity

The video tutorial explains how to verify a trigonometric identity involving π and θ. It begins with an introduction to the identity and a review of the cosine and sine difference formulas. The instructor then applies these formulas to verify the identity, simplifying the expression step by step. The tutorial concludes with a successful verification, demonstrating that the left side equals the right side.

What simplifications occur when evaluating the sine and cosine values?

What conclusion is reached at the end of the verification process?