What is the definition of domain?
A set of input values (all values of x).
The cost to manufacture x number of chairs can be represented by the function C(x)=36x. In this context, what does the statement C(63)=2268 mean?
FILL IN THE BLANK: It costs _____ to make _____ chairs.
It costs $2268 to make 63 chairs.
Find the value of x when f(x) = 12:
f(x) = 2x+6
x = 3
Is it a function? {(2, 3), (4, 5), ( -2, 6)}
Yes, each input has exactly one output.
The cost for x gallons of heating oil can be represented by the function f(x)=4x+6. In the context of the problem, fill in the blank with the correct meaning of f(5) = 26.
It costs _____ to get _____ gallons of heating oil.
It costs $26 to get 5 gallons of heating oil.
Find the value of x when f(x) = 12:
f(x) = -2x+6
x = -3

Not a function
What describes a function?
a) An input and output relationship
b) An independent and dependent variable relationship
c) For every domain value, there is one range value to go with it
d) all of the above
All of the above!
Evaluate f(-6) if f(x)=x - 9
f(-6) = -15
Jeremy is buying a lot of disc golf frisbees. The function f(x) = 15x + 5 represents the cost f(x) of buying x frisbees.
How much will it cost Jeremy if he wants to buy 10 frisbees?
f(10) = 15(10) + 5
f(10) = 150 + 5
f(10) = $155
Find the value of x when f(x) = 12:
f(x) = -2x-6
x = -9
| x | y |
| 2 | 4 |
| 1 | 5 |
| 2 | 6 |
Sort the following terms into two groups:
Independent variable
Dependent variable
y-value
x-value
input
output
{independent variable, x-value, input}
{dependent variable, y-value, output}
Evaluate f(4) if f(x)=25 - 4x
f(4) = 9
Keith is driving from Orlando to Tampa for a disc golf competition. He has 145 miles to drive and is traveling at 45mph.
The function f(x) = 145 - 45x represents the distance f(x) Keith has left to drive after x hours of driving. After 3 hours, how much farther does Keith have to drive?
f(3) = 145 - 45(3)
f(3) = 10
Keith has 10 miles to go
Find the value of x when f(x) = 12:
f(x) = -2(x+6)
x = -12
Is it a function? Justify your answer.
Yes, it passes the Vertical Line Test.
Is the following situation classified as discrete or continuous?
The temperature is slowly rising in a classroom where the air conditioning has gone out. It started at 72-degrees and now it's 80-degrees!
Continuous, because temperature doesn't rise 1-degree at a time. Decimal values for temperature exist.
Evaluate f(3) if f(x)=3(x + 5) - 2
f(3) = 22
Does this situation represent a function?
Input: the number of students in one of Mrs. Piper's classes
Output: the average score on the most recent quiz for the students in that class
No...she could have two classes with the same number of students but different average scores.
Find the value of x when f(x) = 12:
f(x) = -2(-x-6)
x = 0

Function!
It's ok that the 4 and 2 both point to 9.