1. If you are done: Take the algebra book from under your seat.
Begin to read about functions:
Page 46

2. Writing Functions
September 17, 2014 Can I create equations in two variables to represent the relationship between two variables?

3. You buy a printer for $80 and then pay $15 for each ink cartridge that you use. A function relating the cost, Y (in dollars), of operating the printer to the number of cartridges used, x: Y =

4. Let’s talk about the parts of this function
Domain: Set of input values
Range: Set of output values

5. Complete the table to represent the total cost for 0 to 4 cartridges.
Number of cartridges
Total Cost 1 2 3 4

6. Graph the function from the table CHOOSE A REASONABLE SCALE

7. Let’s analyze this function
What is the initial value of the cost function? What does it represent?
What number of cartridges corresponds to the initial cost?
Define the domain.
Define the range.
What would the total cost be if you purchased 17 cartridges?
How would your cost change if the printer cost $90?

8. Now you try:
Andrea receives a $40 gift card to use a town pool. It costs her $8 per visit to swim. A function relating the value of the gift card to the number of visits. Write an function to represent this situation. Make a table of values. Graph the function

9. Turn and talk What is the initial value? (1 talk to 2)
What is the difference between a given card value and the previous card value? (2 talk to 1)
Identify the domain and the range of the function using set notation (1 talk to 2)
Is it possible for the card to have a value of $35? Why or why not? (2 talk to 1)

10. Work on Explore 1 in your groups. Be ready to share.
On Your Own:
Work on Explore 1 in your groups. Be ready to share.