Create a right triangle to evaluate the composition of a function and its inverse

The video tutorial explains how to express the sine of an angle, referred to as alpha, and explores the geometric and algebraic methods to find the cosine of alpha. It involves drawing a triangle, calculating the adjacent side, and simplifying expressions by rationalizing denominators.

What is the relationship between the sides of the triangle and the sine function?

Describe how to simplify the expression involving X and the square root.