Download Functions and Linear Equations

Input/Output tables
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.
INPUT
FUNCTION
RULE
OUTPUT
Function Table
• You can organize the input numbers,
output numbers, and function rule in a
function table.
• Lets Try an example
Example
• Suppose you earn $5
each week. Make a
function table to show
your total earnings
after 4 weeks.
Input
(# of
weeks)
1
Function Output
rule
(total
( x 5)
earnings)
5x1
5
2
5x2
10
3
5x3
15
4
5x4
20
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.
Example
Function
rule
Output
x
X-3
y
1
1-3
-2
0
0-3
-3
-1
-1 - 3
-4
-2
-2 - 3
-5
Input
• 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)
Example
Function
rule
Output
x
2x
y
1
2(1)
2
2
2(2)
4
3
2(3)
6
4
2(4)
8
Input
• 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)
Example
Input
• 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
Function
rule
Output
2x -1
y
1
2(1)-1 1
2
2(2)-1
3
2(3)-1 5
4
2(4)-1
3
7
Your Turn
• Make a function table and graph the
equation.
• y = 3x2 - 2