Understanding Angles and Trigonometric Functions

The video tutorial explains how to determine the reference angle for 120 degrees, identify the quadrant of its terminal side, and calculate the sine, cosine, and tangent values using both a reference triangle and the unit circle. The tutorial provides a step-by-step approach to sketching angles, understanding quadrants, and verifying trigonometric values.

What is the reference angle for 120 degrees?

• 30 degrees

• 90 degrees

• 60 degrees

• 45 degrees

In which quadrant does the terminal side of a 120-degree angle lie?

• Quadrant III

• Quadrant II

• Quadrant IV

• Quadrant I

What is the sine of 120 degrees using a reference triangle?

• Negative square root of 3/2

• 1/2

• Square root of 3/2

• Negative 1/2

What is the cosine of 120 degrees using a reference triangle?

• 1/2

• Square root of 3/2

• Negative 1/2

• Negative square root of 3/2

What is the tangent of 120 degrees using a reference triangle?

• Square root of 3

• Negative square root of 3

• 1

• Negative 1

What is the sine of 120 degrees using the unit circle?

• 1/2

• Negative square root of 3/2

• Square root of 3/2

• Negative 1/2

What is the cosine of 120 degrees using the unit circle?

• Negative 1/2

• Square root of 3/2

• 1/2

• Negative square root of 3/2

What is the tangent of 120 degrees using the unit circle?

• Negative square root of 3

• Negative 1

• 1

• Square root of 3

How do the trigonometric values obtained from the reference triangle compare to those from the unit circle?

• They are the same

• They are different

• They are unrelated

• They are opposite

What is the importance of verifying trigonometric values using different methods?

• To make calculations harder

• To avoid using calculators

• To ensure accuracy

• To confuse students