2. Main Idea and New Vocabulary
Example 1: Real-World Example: Graph a Function
Example 2: Graph a Function
Key Concept: Representing Functions
Example 3: Continuous and Discrete Data
Example 4: Continuous and Discrete Data
Example 5: Continuous and Discrete Data
Lesson Menu

3. Represent linear functions using function tables and graphs
Represent linear functions using function tables and graphs. Determine whether a set of data is continuous or discrete.
linear function
continuous data
discrete data
Main Idea/Vocabulary

4. Step 1 Choose values for x and substitute them to find y.
Graph a Function
MUSIC During a clearance sale, a music store is selling CDs for $3 and tapes for $1. Graph the function y = 6 – 3x to find how many CDs x and tapes y Bill can buy with $6.
Step 1 Choose values for x and substitute them to find y.
Example 1

5. Step 2 Graph the ordered pairs (x, y).
Graph a Function
Step 2 Graph the ordered pairs (x, y).
Bill cannot buy negative amounts, so (3, –3) is not a solution.
Answer: Therefore, he can buy 0 CDs and 6 tapes, 1 CD and 3 tapes, or 2 CDs and 0 tapes.
Example 1

6. GIFTS A stationery store sells rolls of gift bags for $3 each and birthday cards for $1 each. Rachel has $10 to spend on b gift bags and c cards. Graph the equation 10 – 3b to find how many gift bags and cards Rachel can buy. Which of the following combinations is not possible?
A. 0 gift bags and 10 cards
B. 1 gift bag and 7 cards
C. 2 gift bags and 5 cards
D. 3 gift bags and 1 card
Example 1 CYP

7. Graph a Function Graph y = x – 3.
Select any four values for the domain x. Substitute these values for x to find the value of y.
Example 2

8. Graph each ordered pair. Draw a line that passes through each point.
Graph a Function
Graph each ordered pair. Draw a line that passes through each point.
Answer:
The line is the complete graph of the function. The ordered pair corresponding to any point on the line is a solution of the equation y = x – 3.
Example 2

9. y = x – 3 Write the function.
Graph a Function
Check It appears that (4, 1) is also a solution. Check this by substitution.
y = x – 3 Write the function.
1 = 4 – 3 Replace x with –2 and y with 0. ?
1 = 1 Simplify. 
Example 2

10. Graph y = x + 4.
A. B.
C. D.
Example 2 CYP

11. Key Concept

12. Continuous and Discrete Data
HEALTH CLUB Each member of a health club receives two free guest passes. Write a function to represent the situation.
Let p represent the number of free passes and m represent the number of members.
Answer: The function is p = 2m.
Example 3

13. ART The cost for admission to the art museum is $4 per person
ART The cost for admission to the art museum is $4 per person. Write a function to represent this situation. Let c represent the cost and p represent the number of people.
A. c = 4p
B. c = 4 + p
C. p = 4 + c
D. p = 4c
Example 3 CYP

14. Continuous and Discrete Data
HEALTH CLUB Each member of a health club receives two free guest passes. Make a function table to show the number of guest passes given out to 10, 20, 30, and 40 members.
Answer:
Example 4

15. ART The cost for admission to the art museum is $4 per person
ART The cost for admission to the art museum is $4 per person. Make a function table to show the cost for 5, 10, 15, and 20 people. Let c represent the cost and p represent the number of people.
A. B.
C. D.
Example 4 CYP

16. Continuous and Discrete Data
HEALTH CLUB Each member of a health club receives two free guest passes. Graph the function. Is the function continuous or discrete? Explain.
Use the ordered pairs from the function table to graph the function.
Example 5

17. Continuous and Discrete Data
There can only be a whole number amount of health club members. The function is discrete. So, the points are not connected.
Answer: The function is discrete. The number of health club members can only be represented by whole numbers.
Example 5

18. ART The cost for admission to the art museum is $4 per person
ART The cost for admission to the art museum is $4 per person. Graph the function. Is the function continuous or discreet.
A. B.
C. D.
continuous;
discrete;
Example 5 CYP