1. Unit Circle / Circular Functions
terminal
arm/ side
initial arm/ side
Let the terminal arm be "r" = 1 and rotate it once,
this results in a circle with a radius = 1 unit in length,
Unit Circle
Standard Position of
Initial arm lays
on the x-axis
the origin

3. Coterminal Angles
angles which share the same terminal side/ arm
ex. Give two coterminal angles for 30

4. Measurement of Angles
3 Systems
- unit symbol is
o
- has no unit symbol
r
s-
ra diu
= arc length = s
The central angle is subtended or "covered" by an arc length
(for a given radius)
1 revolution (once around) = 360
C=2 r
in rads = rads or radians
or 2 (3.14) = 6.28 rads

5. The Connection -> Rads to Degrees
Degrees Radians
(exact values)

6. Converting Degrees Radians
Recall
ex 1) How many radian is
(in -terms)

7. ex 2) How many degrees is