Evaluate inverse cosine in a composition by creating a right triangle

The video tutorial explains how to evaluate the sine of the cosine inverse of 1/3 by constructing a triangle. It guides through creating a triangle to find an unknown angle, Theta, and then uses the Pythagorean theorem to calculate the sine of this angle. The tutorial concludes with a final example and mentions a quiz for further practice.

What is the value of y when you solve the equation 3^2 + 1^2 = y^2?

What is the significance of the angle being equal to sqrt(2)/2 in trigonometric functions?