Co-terminal and Reference Angles

This video tutorial explains how to find exact trigonometric values using co-terminal angles. It covers the concept of co-terminal angles, which are angles that end in the same position, and demonstrates how to convert negative angles or angles greater than 360° into a standard 0 to 360° range. The tutorial provides two examples: finding the sine of -225° and the cosine of 600°, illustrating the process of adjusting angles and using reference angles to determine exact values without decimals. The video emphasizes the use of a trigonometric chart for common angles like 30°, 45°, and 60°.

What is the purpose of finding co-terminal angles?

• To find angles with the same terminal side

• To simplify angle measurements

• To convert angles to radians

• To measure angles in degrees

What does a co-terminal angle represent?

• An angle that is always negative

• An angle that is greater than 360 degrees

• An angle that ends in the same position as another

• An angle that is always positive

How do you convert a negative angle to a positive co-terminal angle?

• Divide by 2

• Multiply by -1

• Add 360 degrees

• Subtract 180 degrees

What is the co-terminal angle of -225 degrees?

• 45 degrees

• 225 degrees

• 315 degrees

• 135 degrees

Why is it important to use a chart for exact trigonometric values?

• To avoid using decimals

• To convert angles to radians

• To find approximate values

• To measure angles in degrees

Which quadrant does the angle 135 degrees fall into?

• Quadrant 1

• Quadrant 4

• Quadrant 2

• Quadrant 3

What is the reference angle for 135 degrees?

• 30 degrees

• 45 degrees

• 90 degrees

• 60 degrees

What is the sine of 45 degrees?

• 0

• √2/2

• √3/2

• 1/2

What is the significance of a reference angle?

• It is used to find the exact trigonometric value

• It is always 90 degrees

• It helps in converting angles to radians

• It determines the quadrant of the angle

What is the sine of 135 degrees?

• √3/2

• 1/2

• √2/2

• 0