This document discusses periodic functions and conversions between radians and degrees. It asks why there are 360 degrees in a circle and what the most natural way to measure angles is. It also provides examples of converting between radians and degrees and asks what the term "periodic" means, relating it to examples like the heartbeat, tides, and orbits.

1. Periodic Functions
Why are there 360° in a circle?
What is the most quot;naturalquot; way to measure angles?
Photo Source: Circles

2. Area
Circumference

3. How do we convert between radians and degrees?
D is an angle in degrees
R is an angle in radians
Examples:
Find 20° in radians ...
Find 30° in radians ...

4. Find 250° in radians ... Find in degrees ...

5. Find in degrees ...

6. Find -18° in radians ... Find in degrees ...

7. Find -18° in radians ... Find in degrees ...

9. What does periodic mean?
Clock photo source

10. What does periodic mean?
Jupiter and Io photo source

11. What does periodic mean?
Low tide photo source

12. What does periodic mean?
Baby heartbeat photo source

13. What does periodic mean?
Heartbeat of Trees photo source

14. The sine curve (graph) ...