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.

What is the x-coordinate on the unit circle when the cosine of theta is -1?

• 0

• π

• 1

• -1

Which angle between 0 and 2π has a cosine value of -1?

• 2π

• π/2

• π

• 0

If you are asked to find all solutions for cosine of theta equals -1, what would be the general form?

• π/2 + 2πR

• 2π + πR

• π + 2πR

• 0 + πR

What does the variable R represent in the general solution π + 2πR?

• The angle in degrees

• The number of times the circle is traversed

• The radius of the circle

• A constant

What is the significance of adding 2π to the angle π in the context of the unit circle?

• It changes the cosine value to 0

• It returns to the same point on the circle

• It doubles the angle

• It changes the sine value to 1