Exploring the Unit Circle in Trigonometry

The video tutorial explains the concept of the unit circle, a circle with a radius of one, and its significance in trigonometry. It covers how to find sine and cosine values using the unit circle, focusing on common angles in the first quadrant. The tutorial also discusses the use of reference angles and symmetry to evaluate trigonometric functions without memorizing the entire unit circle. Additionally, it explains how to work with radians and provides examples of evaluating trigonometric functions using these concepts.

What is the radius of the unit circle?

• 1

• π

• 2

• 0

What is the value of sine at a 45-degree angle in the unit circle?

• 1/2

• √2/2

• √3/2

• 0

What are the x and y values at a 30-degree angle in the unit circle?

• x = √3/2, y = 1/2

• x = 0, y = 1

• x = √2/2, y = √2/2

• x = 1/2, y = √3/2

How do you find the cosine of 180 degrees using the unit circle?

• √2/2

• 0

• 1

• -1

What is the sine of 135 degrees?

• 1/2

• -√2/2

• √2/2

• -1/2

What is the cosine of 225 degrees?

• √3/2

• -√3/2

• -√2/2

• √2/2

What is the value of sine pi over 3?

• √3/2

• 1/2

• -√3/2

• √2/2

What is the cosine of 5 pi over 3?

• -√3/2

• √3/2

• -1/2

• 1/2

What is the sine of 11 pi over 6?

• -1/2

• √3/2

• 1/2

• -√3/2

What is the cosine of 7 pi over 6?

• 1/2

• -1/2

• √3/2

• -√3/2