Solving a trigonometric equation with cosine equal to negative one

The video tutorial explains how to evaluate the cosine of an angle when it equals -1. It begins by discussing the unit circle and identifying the X coordinate where the angle intersects. The tutorial then determines the angle between 0 and 2π, which is π, and explains how to find all solutions without constraints, resulting in π plus 2πR, where R is a variable representing the number of rotations. The video concludes with a summary of the solution process.

How does adding π and 2π affect the solutions for cosine -1?

What does R represent in the context of finding all solutions for cosine -1?