Trigonometric Functions and Reference Angles in All Four Quadrants

This video tutorial covers evaluating trigonometric functions using reference angles. It explains the concept of coterminal angles and how to determine the signs of trigonometric functions in different quadrants. The tutorial also details how to use reference angles to calculate trigonometric ratios, even for angles beyond 360 degrees. Examples are provided to illustrate the process, emphasizing the importance of drawing reference angles correctly to avoid errors in calculations.

What is the purpose of using reference angles in trigonometry?

• To simplify calculations by using a calculator

• To evaluate trigonometric functions of angles in all quadrants

• To limit angles to between 0 and 90 degrees

• To avoid using the unit circle

Which trigonometric functions are positive where x is positive?

• Tangent and cotangent

• Cosine and secant

• Sine and tangent

• Sine and cosecant

How is the reference angle determined in the second quadrant?

• Subtract the angle from 360 degrees

• Subtract the angle from 180 degrees

• Add the angle to 180 degrees

• Add the angle to 360 degrees

What is the reference angle for an angle of 460 degrees?

• 80 degrees

• 40 degrees

• 60 degrees

• 100 degrees

How do you determine if the trig ratio of a reference angle should be positive or negative?

• By checking the unit circle

• By using a calculator

• By using a simple trig chart

• By drawing a reference triangle

What is the sine of 120 degrees?

• Negative radical 3 over 2

• Positive radical 3 over 2

• Negative 1 over 2

• Positive 1 over 2

Why is it important to draw the reference angle to the x-axis?

• To ensure the reference angle is in standard position

• To make use of the unit circle

• To avoid incorrect reference angles and trig ratios

• To simplify the calculation process