Trigonometric function

15.5 Outline

1. Definitions
   1. first/second components
   2. function
2. Representations of functions
   1. ordered pairs
   2. mapping
   3. machine
3. Functional notation
   1. domain
   2. range
   3. difference quotient
4. Vertical line test
5. Some important functions (see below)
   1. constant function
   2. linear function
   3. quadratic function
   4. trigonometric function
   5. exponential function
   6. logarithmic function
   7. probability