1. New seating chart today
2 3
1 4

2. The Lame Joke of the day..
What did the traffic light say to the car?
And now it’s time for..
Don’t look I’m changing!

3. Don’t forget!
• Problem of the week can be done for extra
credit.
• See the bulletin board in class, or the
discussion board on echo.

4. Functions
• Definitions
• Examples
• Graphs
• Vocabulary
• Symbols and notation

5. Relation
• Pairs of quantities that are RELATED in some
way.

6. Vocabulary
• Function: A special type of Relation in which
each input value (Domain) is matchup up
with exactly one output value (Range).
Usually we describe a function with an equation.

7. Grading Function

9. Vocabulary
• Function: Rule that assigns each input value
to exactly one output.
Usually we describe a function with an equation.
• Domain: x –values, or input values.
• Range: y – values , or output values.

10. How do we know if a graph is a
function?
• If it passes THE VERTICAL LINE TEST
The vertical line test
1. Move a vertical line across the entire graph
from left to right.
2. If it intersects the graph only ONCE in all
locations, then it is a function.

11. Is this a function?

12. Is this a function?

13. Is this a function?

14. What is the Domain and Range?

15. What is the Domain and Range?

16. What is the Domain and Range?

17. Function notation
)(xf
Whatever is in the parentheses gets plugged into
the function.

18. Practice
1. Is a function represented? If so what is the
domain and range.
a. (2,-4) (4,4) (6,-1) (5,0) (1,6) (2,4) (3, -2)
b.
2. If , then find f (0) , f (-2) , and f (3a)5)( 2
xxf

19. Finding the domain from the equation
Example: What is the domain of the function given
by
Functions only have real number outputs.
Anything that gives an imaginary number or a
zero denominator is a restriction.
How to find the domain:
Assume that the domain is the set of all real
numbers except for the restrictions.
5)( xxf

20. Examples
• What is the domain?
• What is the domain?
7
2
)(
x
xf
9
7
)( 2
x
xf

21. More challenging examples
• What is the domain?
• What is the domain?
4
32
)(
xx
xf
6
9
)(
x
x
xf

22. Practice
• What is the domain?
• What is the domain?
• What is the domain?
xx
xf
5
5
)( 2
7)( 2
xxf
3
7)( xxf