Coterminal and Reference Angles

The video tutorial covers coterminal and reference angles. It begins with an introduction to coterminal angles, explaining their properties and how to calculate them in both positive and negative forms. The tutorial then moves on to identifying whether two angles are coterminal. Following this, the concept of reference angles is introduced, with a focus on calculating them in both degrees and radians. The tutorial concludes with practice problems and a reminder to study for an upcoming test.

What is a coterminal angle?

• An angle that is exactly 90 degrees.

• An angle that is always positive.

• An angle that shares the same initial and terminal sides but different measures.

• An angle that is always negative.

How do you find a positive coterminal angle for a given angle in degrees?

• Multiply the angle by 2.

• Add 360 degrees to the given angle.

• Divide the angle by 2.

• Subtract 360 degrees from the given angle.

What is the negative coterminal angle of 74 degrees?

• -286 degrees

• 286 degrees

• -434 degrees

• 434 degrees

Why are there infinite coterminal angles for a given angle?

• Because you can keep adding or subtracting multiples of 360 degrees.

• Because angles can only be positive.

• Because angles can only be negative.

• Because angles are always measured in radians.

How do you determine if two angles are coterminal in radians?

• Check if their difference is a multiple of 2π.

• Check if their sum is a multiple of 2π.

• Check if their product is a multiple of 2π.

• Check if their quotient is a multiple of 2π.

What is a reference angle?

• The angle that is always 90 degrees.

• The angle that is always 180 degrees.

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

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

Which of the following is NOT a property of a reference angle?

• It must be positive.

• It must be less than 90 degrees.

• It must be in quadrant one.

• It must be greater than 180 degrees.

How do you find the reference angle for 132 degrees?

• Divide 132 by 2.

• Multiply 132 by 2.

• Add 132 to 180.

• Subtract 132 from 180.

What is the reference angle for 232 degrees?

• 52 degrees

• 48 degrees

• 132 degrees

• 128 degrees

How do you find the reference angle for a negative angle?

• Multiply the negative angle by -1.

• Add 360 degrees to the negative angle.

• Find the positive equivalent and then determine the reference angle.

• Subtract 360 degrees from the negative angle.