Evaluate the trig function and inverse function

The video tutorial explains the concept of inverse sine and its application in trigonometry, particularly when dealing with non-unit circles. It discusses constructing triangles with given hypotenuse and Y values, and the importance of sine restrictions. The tutorial demonstrates using the inverse sine function to determine valid triangles and applies the Pythagorean theorem to solve for missing sides. Finally, it calculates the cosine of an angle and reviews the relationships between sine, cosine, and their respective triangle sides.

What is the Pythagorean theorem and how is it applied in this context?

Describe the difference between sine and cosine in terms of their definitions.