Equivalent Angles and Negative Radius

The video tutorial explains how to express polar coordinates in four different ways. It covers the use of positive and negative angles, the concept of negative radius, and how to convert these coordinates using degrees. Examples are provided to illustrate these concepts, including the use of the unit circle and the addition or subtraction of pi and 2pi to switch between positive and negative angles.

What is one way to write the same polar coordinate differently?

• Keep the radius positive and adjust the angle

• Change the radius to zero

• Use a different unit for the radius

• Convert the coordinate to Cartesian form

How can you convert a negative angle to a positive angle in polar coordinates?

• Subtract 2π (360 degrees)

• Add 2π (360 degrees)

• Add 180 degrees

• Subtract 180 degrees

How do you convert a positive angle to a negative angle in polar coordinates?

• Add 2π (360 degrees)

• Subtract π (180 degrees)

• Add π (180 degrees)

• Subtract 2π (360 degrees)

What is the result of adding 2π to a negative angle?

• The angle becomes zero

• The angle becomes undefined

• The angle becomes positive

• The angle remains negative

What happens when you make the radius negative in polar coordinates?

• The point moves to the origin

• The point reflects over the pole

• The angle becomes negative

• The coordinate becomes undefined

In the example given, what is the positive angle equivalent of -3π/4?

• π/4

• 7π/4

• 5π/4

• 3π/4

What is the angle opposite to 45 degrees when using a negative radius?

• 135 degrees

• 225 degrees

• 315 degrees

• 90 degrees

What is the equivalent angle of 7π/4 when using a negative radius?

• 3π/4

• 9π/4

• π/4

• 5π/4

What is the angle opposite to 225 degrees when using a negative radius?

• 315 degrees

• 90 degrees

• 135 degrees

• 45 degrees

What is the equivalent angle of 3π/4 when using a negative radius?

• 7π/4

• 9π/4

• π/4

• 5π/4