1. A relation is a set of ordered pairs.
What is a Relation?
Graphing
A relation is a set of ordered pairs.
Mapping [x] [y]
1 ] [6
2 ] [6
-2] [7
4] [7
A relation is a function when the y value is with only one x value.
YES NO
1 3
2 3
24
A relation is a function when it passes the vertical line test.
These can be expressed as a table of value, a graph, a map, and many more!

2. Domains and Functions The domain of a function is all x values.
The range of a function is all the y values.
Examples
Auto insurance costs increase with each accident and traffic violation.
A kid is buying several DVDs that cost $12 each.
The rule of functions is each domain value with exactly one range value.