Find the reference angle and sketch both angles in standard position

The video tutorial explains how to find the reference angle for a given negative angle. It begins by defining the reference angle and sketching the angle in standard position. The tutorial then addresses the challenge of using negative angles and introduces the concept of coterminal angles to find a positive equivalent. By adding 360 degrees to the negative angle, a positive coterminal angle is obtained, which is then used to calculate the reference angle. The process is demonstrated with an example, showing how to apply the formula for the third quadrant to find the reference angle.

What is the first step in finding a reference angle for a given angle?

• Determine the quadrant of the angle

• Find the sine of the angle

• Sketch the angle in standard position

• Convert the angle to radians

Why is it challenging to use a negative angle directly to find a reference angle?

• Negative angles do not have terminal sides

• Negative angles are not defined in trigonometry

• Negative angles cannot be plugged into the reference angle formula

• Negative angles are always in the first quadrant

How do you find a positive coterminal angle for a given negative angle?

• Add 360 degrees to the negative angle

• Divide the negative angle by 2

• Multiply the negative angle by -1

• Subtract 180 degrees from the negative angle

What is the reference angle for a positive coterminal angle of 215 degrees?

• 35 degrees

• 55 degrees

• 25 degrees

• 45 degrees

Which quadrant is used to find the reference angle for a positive coterminal angle of 215 degrees?

• Fourth quadrant

• Third quadrant

• Second quadrant

• First quadrant