4.1-4.2 (Angles And The Unit Circle)

Question 1

What is the terminal arm?

Answer 1

The arm connected to the initial arm, can lie anywhere on the x axis. Rotates to it’s final position in a clockwise or counterclockwise direction

Question 2

What determines the measure of an angle?

Answer 2

The amount of rotation from the initial arm to the terminal arm. Measured in degrees and radians. 360 degrees in a circle or 2 pi

Question 3

What is a central angle?

Answer 3

When the vertex is at the centre of the circle

Question 4

What is the relationship between radians and degrees?

Answer 4

To convert degrees to radians multiply by
Pi / 180

To convert radians to degrees multiply by 180 / pi

Question 5

What does 60 degrees equal in radians?

Answer 5

Pi / 3

Question 6

What does pi / 4 equal in degrees?

Answer 6

45 degrees

Question 7

What does 30 degrees equal in radians?

Answer 7

Pi / 6

Question 8

What are co-terminal angles?

Answer 8

Angles in standard position with the same terminal arm

Question 9

How do you find co-terminal angles?

Answer 9

Angle plus or minus 360 degrees / 2 pi

Question 10

What is the general form of co-terminal angles?

Answer 10

Theta plus or minus (360 degrees)n
Theta plus or minus 2 pi (n)

Question 11

What is the arc length of a circle?

Answer 11

A portion of the circumference of a circle

Question 12

What is the formula for arc length of a circle?

Answer 12

Arc = theta(radius)

Theta must be measured in radians

Question 13

What is the unit circle?

Answer 13

A circle with a radius of 1 unit at the origin on the Cartesian plane

Question 14

How does the Pythagorean Theorem apply to unit circles?

Answer 14

X^2 + Y^2 = 1