Evaluating the composition of inverse functions trigonometry

The video tutorial explains how to evaluate the inverse sine function, focusing on the correct range for evaluation. It discusses the sine of 2X, emphasizing the relationship between the opposite side and hypotenuse. The tutorial guides viewers through determining the sides of a triangle, ensuring the cosine remains positive. It includes solving for the adjacent side using equations and concludes with finding the cosine and the final answer.

How do you find the length of the adjacent side in the triangle described?

What is the final expression for cosine derived in the text?