1. Input/Output tables

2. Function A relationship where one thing depends on another.
In a function you start with an input number, perform an operation, and get an output number.
FUNCTION RULE
INPUT
OUTPUT

3. Function Table
You can organize the input numbers, output numbers, and function rule in a function table.
Lets Try an example

4. Example
Suppose you earn $5 each week. Make a function table to show your total earnings after 4 weeks.
Input
(# of weeks)
Function rule
( x 5)
Output
(total earnings) 1
5 x 1 5 2
5 x 2 10 3
5 x 3 15 4
5 x 4 20

5. Words to Know Domain= the input values Range= the output values
In our example the domain would be written as
{ 1, 2, 3, 4 } and the range would be written as
{ 5, 10, 15, 20 }
The domain or input represents the x value and the range the y value. Together they form an ordered pair.

6. Example
Function rule
Input
Output
Make a function table and graph the equation.
y = x -3
Domain = {1,0,-1,-2}
Range = {-2,-3,-4,-5}
Ordered pairs =
(1, -2) (0, -3) (-1,-4)
(-2, -5) x
X-3 y 1
1 - 3 -2
0 - 3 -3
-1 - 3 -1 -4 -2
-2 - 3 -5

8. Example
Function rule
Input
Output
Make a function table and graph the equation.
y = 2x
Domain = {1,2,3,4}
Range = {2,4,6,8}
Ordered pairs =
(1, 2) (2, 4) (3,6)
(4, 8) x 2x y 1
2(1) 2 2
2(2) 4
2(3) 3 6 4
2(4) 8

10. Example
Function rule
Input
Output
Make a function table and graph the equation.
y = 2x -1
Domain = {1,2,3,4}
Range = {1,3,5,7}
Ordered pairs =
(1, 1) (2, 3) (3,5)
(4, 7) x
2x -1 y 1
2(1)-1 1 2
2(2)-1 3
2(3)-1 3 5 4
2(4)-1 7

12. Your Turn
Make a function table and graph the equation.
y = 3x2 - 2