Reference Angles and Trigonometric Functions

This video tutorial covers Section 12.3 on trigonometric functions of general angles. It begins with an introduction to using trigonometric functions beyond right triangles, focusing on points on the terminal side of an angle. The tutorial explains how to calculate the six trigonometric functions using the Pythagorean theorem and given coordinate points. It also covers the concept of reference angles, explaining how to determine them in different quadrants and both degrees and radians. The video includes examples and practice problems to reinforce understanding, concluding with a summary of the key points covered.

What is the main difference between using trigonometric functions with right triangles and with general angles?

• Right triangles use angles, general angles use points on a plane.

• Right triangles use points, general angles use angles.

• Right triangles use degrees, general angles use radians.

• Right triangles use radians, general angles use degrees.

Which of the following is NOT a trigonometric function?

• Cosine

• Secant

• Sine

• Tangent

If the point on the terminal side of an angle is (8, -15), what is the value of R?

• 15

• 17

• 8

• 289

What is the sine of an angle if the point on the terminal side is (8, -15) and R is 17?

• 8/17

• 17/8

• -15/17

• 15/17

What is a reference angle?

• The angle between the terminal side and the x-axis.

• The angle between the initial side and the y-axis.

• The angle between the terminal side and the y-axis.

• The angle between the initial side and the x-axis.

In which quadrant does an angle of 330° lie?

• Quadrant 4

• Quadrant 1

• Quadrant 2

• Quadrant 3

How do you find a co-terminal angle for -200°?

• Add 180°

• Subtract 180°

• Add 360°

• Subtract 360°

What is the reference angle for 330°?

• 90°

• 60°

• 120°

• 30°

If an angle is in the third quadrant, how do you find its reference angle in degrees?

• Subtract 360° from the angle

• Subtract the angle from 360°

• Subtract 180° from the angle

• Subtract the angle from 180°

What is the reference angle for 5π/3 radians?

• π/6

• 2π/3

• π/3

• 5π/6