1. FUNCTIONS

2. Identifying a Function by Graphing
If the relation is a function, then any vertical line passes through ONLY 1 point on the graph.
If you can find a vertical line that passes through two points on the graph, then the relation is not a function.
This is called the vertical line test.

4. What is a “function”? Domain…the numbers you plug in (the x values)
Range….the results (the y values)
For each member of the domain, there is exactly one member in the range. Therefore, domain numbers CANNOT be repeated, but range numbers CAN be repeated.

6. Identify the domain and range values
Identify the domain and range values. Then tell whether the relation is a function.
(0,1) (1,2) (2,2) (3,4)
(0,0) (-1,0) (0,-1) (-1,-1)

7. Identify the domain and range values
Identify the domain and range values. Then tell whether the relation is a function.
(-2,3) (2,2) (2,-2)
(-5,-4) (0,-4) (5,-4)

8. Water Pressure (lbs/ft2)
The table shows the water pressure as a scuba diver descends. A.) Do these data represent a function? Explain. B.) Describe how water pressure is related to depth.
Depth (ft)
Water Pressure (lbs/ft2) 1
62.4 2
124.8 3
187.2 4
249.6

9. Classwork: textbook p.361 #1-8

10. HOMEWORK textbook p. 361 #10-24 evens
HOMEWORK textbook p.361 #10-24 evens *Use the explanation (blue sentences under the table of values) on p.359 as to why or why not the ordered pairs are a function.