1. Section 8.1 Relations and Functions
Algebra Concepts
Section 8.1
Relations and Functions

2. Warmup
Name the ordered pairs!

3. What are relatives?

4. Relation-numbers that are paired together
Numbers are written as ordered pairs.
Each student provides the minutes they studied for a test and the grade they got.
One of the answers could be (60,85)

5. All the ordered pairs of the relation can be written as a set.
{(60,85),(20,73),(40,100),(45,88),(0,67),(15,81)}

6. Domain- set of first (x) coordinates
Range- set of second (y) coordinates
{(60,85),(20,73),(40,100),(45,88),(0,67),(15,81)}
Domain {60,20,40,45,0,15}
Range {85,73,100,88,67,81}

7. Function- special relation where every x has a unique y
In a function, every x can be paired with only one y
It is okay for a y to paired with more than one x.

8. Is this a function? This is not a function because 2 is paired with
two different numbers.

9. Which one is a function?

10. When there is a list of ordered pairs or a table of ordered pairs, look for any x value that is repeated.
If x does not repeat→a function.
If x does repeat→ no function.

11. Is the graph a function?

12. When looking at a graph, you can use the Vertical Line Test to decide if the graph is a function.

13. If a vertical line passes through more than one point, the graph is not a function.

14. When one quantity depends on another, we say “One quantity (the range value) is a function of another quantity (the domain value).”

15. Real life functions
Is the number of trips a mother makes to a dance studio a function of the number of dance classes her daughter goes to?

16. Is the price you pay at the cash register a function of how many subs you buy?

18. Assignment #48
Pg #1-7, 14-20, 29-31