Understanding the Cosine Function

The video tutorial illustrates the graph of the cosine function using the unit circle. It explains how the cosine function is represented by the x-coordinate of a point on the unit circle where the terminal side of an angle intersects. The video demonstrates cosine values at key angles: 0, 90, 180, 270, and 360 degrees, showing how these values are plotted on a coordinate plane. It also discusses the domain and range of the cosine function, emphasizing that the domain is all real numbers and the range is from -1 to 1. The tutorial includes an animation to visualize these concepts.

What is the primary goal of the video tutorial?

• To explain the sine function

• To illustrate the graph of the cosine function using the unit circle

• To demonstrate the tangent function

• To discuss trigonometric identities

What is the radius of the unit circle?

• 0.5

• 2

• 1

• 3

At 0 degrees, what is the cosine value?

• 0.5

• -1

• 0

• 1

What is the cosine value at 90 degrees?

• 1

• 0.5

• -1

• 0

At 180 degrees, what point does the terminal side intersect on the unit circle?

• (0,1)

• (1,0)

• (0,-1)

• (-1,0)

What is the cosine value at 270 degrees?

• 0.5

• -1

• 0

• 1

What is the cosine value after one complete revolution (360 degrees)?

• 0.5

• -1

• 1

• 0

What is the range of the cosine function?

• -2 to 2

• 0 to 2

• -1 to 1

• 0 to 1

What is the domain of the cosine function?

• 0 to 180 degrees

• -1 to 1

• All real numbers

• 0 to 360 degrees

What does the animation primarily illustrate?

• The sine function

• The tangent function

• The secant function

• The cosine function using the unit circle