Download Function Notation

Function Notation
Warm Up
Determine the Domain and Range of the following set of ordered pairs. Is
the set of ordered pairs a function? Why or why not?
{ (3 , 2) , (4 , 3) , (1 , 4) , (2 , 3) }
Remember: The domain of a relation is all the input values or x values. These values
are the first numbers in the ordered pairs. The Range of a relation is all the output
values or y values. These values are the second numbers in the ordered pairs.
Domain: {3, 4, 1, 2}
Range: {2, 3, 4, 3}
Remember that if a relation is a function, no x value can repeat. Looking at our
Domain, do any numbers repeat?
NO. So our relation is a function because no x values repeat.
• The typical notation for a
function is f(x).
• This is read as “f of x”
because it is a Function of X.
• THIS DOES NOT MEAN
f times x.
Function Notation
Name of
the function
Tells what number to
plug in.
{
f(x) = 3x + 4
f(x) means the output of the
functions f then the input is
x. We often refer to this as y.
THE FUNCTION
f(x) = 2x - 1
Input (x)
Function ( 2x – 1 )
Output (y)
-2
f(-2) = 2(-2) - 1
-5
-1
f(-1) = 2(-1) - 1
-3
0
f(0) = 2(0) - 1
-1
1
f(1) = 2(1) - 1
1
2
f(2) = 2(2) - 1
3
f(x) = 3x +2
Input (x)
-2
-1
Function ( 3x + 2 )
f(-2) = 3(-2) + 2
Output (y)
Ordered pair (x , y)
-4
-1
(-2 , -4)
(-1 , -1)
2
(0 , 2)
0
f(-1) = 3(-1) + 2
f(0) = 3(0) + 2
1
f(1)
= 3(1) + 2
5
(1 , 5)
2
f(2)
= 3(2) + 2
8
(2 , 8)
Becky is selling Bulldog Shirts at school. It will cost her 500
dollars to make the shirts. To make profit, she is selling the
shirts at $8 a shirt.
Independent variable : Number of T shirts sold (t)
Dependent variable :
Profit (P)
The profit from selling t number of shirts is described by the following function.
P( t ) = 8t – 500
Find P(70)
P(70) = 8(70) – 500 = 60