1. Chapter 2.1
Functions

2. A function is a relation that has one output for each input
A function is a relation that has one output for each input. The input value is called the domain and the output value is called the range.
Several ways to show a function.
Mapping:
Ordered Pairs:
Domain:
Range:
(Jack, $75)
(Emiry, $150)
(Raylon, $75)
Jack
Emiry
Raylon
$75
$100
$150
Graph:

3. What is NOT a function. Mapping: Ordered Pairs: Domain: Range:
(Jack, $75)
(Emiry, $150)
(Raylon, $75)
(Emiry, $100)
Jack
Emiry
Raylon
$75
$100
$150
Graph:
Use the Vertical Line test on a graph to determine whether the graph is a function. If the vertical line touches the graph in more than one point, then it is NOT a function.

4. Functions (2,4) (5,6) (9,8) (3,8) (2,4) (5,6) (9,8) (5,8)
You only need to look at the x-coordinates when determining functions. If the x-coordinates has the same value more than once then it is NOT a function.
(2,4) (5,6) (9,8) (3,8)
Function
Not a Function
(2,4) (5,6) (9,8) (5,8)

5. Function or Not a Function?

6. Interval Notation

7. Finding the Domain from a Graph. Write in interval notation.

8. Finding the Domain from a Graph. Write in interval notation.

9. Finding the Domain from a Graph. Write in interval notation.

10. Finding the Domain from a Graph. Write in interval notation.

11. Finding the Domain from a Graph. Write in interval notation.

12. Finding the domain of a function.
“What do we NOT want to happen.”
F(x) = x² + 5x
g(x) = 3x
X² - 4

13. Finding the domain of a function.
“What do we NOT want to happen.”
h(x) = √4 – 3x 3
f(x) =
√4 – 3x