Write an expression as a single trigonometric function using sum and difference formula

The video tutorial explains how to identify and use trigonometric sum and difference formulas, focusing on cosine. It guides through identifying variables U and V, solving the equation, and simplifying the expression to cosine of 8X/7.

What is the significance of the angles U and V in the context of the equation?

How do you derive the cosine of a sum from the given angles?