1. Discrete & Continuous Domains
Holt Course 3 3.3
Glencoe 2-3C

2. Adults $4.00
Children $2.00
8-2xyor1624 +==+ yx
Domain (x-values): 0, 1, 2, 3, 4
Range (y-values): 8, 6, 4, 2, 0
• The domain is discrete because it has
only the numbers 0, 1, 2, 3, and 4. Discrete
graphs are made up of distinct, or
unconnected, points.
• Since there is no such thing as half a
ticket, or one-forth of a ticket the domain
does not include those points between the
points graphed.
Functions shows a recipes mix of adult & children show
tickets.

3. 8-2xyor1624 +==+ yx
Domain (x-values): x ≥ 0 and x ≤ 0
(all numbers from 0 to 4)
Range (y-values): y ≥ 0 and y ≤ 8
(all numbers from 0 to 8)
• The domain is continuous because it
includes all numbers from 0 to 4 on the
number line. Continuous graphs are
made up connected lines or curves.
• Cheese can be divided into fractions
or decimals, so it is shown to be
continuous by using a line to include all
of those points.
Cheddar: $2/lb
Swiss: $4/lb
Functions shows a recipes mix of cheddar & Swiss cheese.

4. •Write a linear function to represent each problem.
•Graph the function.
•Describe the domain and range of each function. Is the
domain discrete or continuous?
You are in charge of reserving hotel rooms for a
baseball team. Each room costs $69, plus $6 tax, per
night. You need each room for two night. You need 10
to 16 rooms. Write a function for the total hotel costs.
yx =150

5. 1500)10(150 =
1650)11(150 =
1800)12(150 =
1950)13(150 =
1050)14(150 =
2250)15(150 =
2400)16(150 =
Discrete

6. •Write a linear function to represent
each problem.
•Graph the function.
•Describe the domain and range of
each function. Is the domain discrete
or continuous?
The airline you are using for the
baseball trip needs an estimate
of the total weight of the team’s
luggage. You determine that
there will be 36 pieces of
luggage and each piece will
weigh from 25 to 45 pounds.
Write a function for the total
weight of the luggage.
1620or x4536x
900or x2536
≤⋅≤
≥⋅≥x

7. 1620x
900x
≤
≥
Continuous

8. Key Idea
• A discrete domain is a set of input values that consists
of only certain numbers in an interval. Like integers 1
to 4.
• A continuous domain is a set of input values that
consists of all numbers in an interval. Like all numbers
1 to 4.
BACK
-3 -2 -1 0 1 2 3 4 5
-3 -2 -1 0 1 2 3 4 5

9. The graphs show the speeds of two cars over time.
Tell which graph corresponds to each situation.
Matching Situations to Graphs
Mr. Lee is traveling on the highway. He pulls over,
stops, then accelerates rapidly as he gets back on
the highway. Graph 2

10. The graphs show the speeds of two cars over time.
Tell which graph corresponds to each situation.
Matching Situations to Graphs
Ms. Montoni slows down as she leaves the main road. She
continues to slow down as she turns onto other streets
and eventually stops in front of her house. Graph 1

11. Check It Out: Example 1A
Tell which graph corresponds to the situation described
below.
Time
Runner’sSpeed
Time
Runner’sSpeed
Time
Runner’sSpeed
Graph 1 Graph 2 Graph 3
Jamie begins the race, and soon feels a pain in a
muscle. He is unable to complete the race.
Graph 2—Jamie is unable to complete the race, so his
speed decreases to zero.

12. Check It Out: Example 1B
Tell which graph corresponds to the situation described
below.
Time
Runner’sSpeed
Time
Runner’sSpeed
Time
Runner’sSpeed
Graph 1 Graph 2 Graph 3
Melissa builds up her speed during the beginning of the
race. She maintains her running speed for the
remainder of the race.
Graph 1—Melissa’s speed increases at the beginning
and then the graph remains constant.

13. Create a graph for the situation. Tell whether the graph is
continuous or discrete.
The table shows
the temperature
inside a car over
time.
Time 8:00 8:30 12:00 12:30
Temp.(F) 71 71 82 74
Car Temperature
64
66
68
70
72
74
76
78
80
82
84
8:00 8:30 12:00 12:30
Time
Temp(F)
Creating a Graph of a Situation
Since every value of
time has a
corresponding altitude,
connect the points.
The graph is continuous.

14. Create a graph for the situation. Tell whether the graph is
continuous or discrete.
A market sells pumpkins
for $5 each.
Pumpkin Cost
0
5
10
15
20
25
30
35
40
0 2 4 6 8
Pumpkins Purchased
Cost($)
Creating a Graph of a Situation
The cost (y-axis)
increases by $5 for each
pumpkin purchased (x-
axis).
Because each person can
only buy whole pumpkins
or none at all, the graph
is distinct points.
The graph is discrete.

15. Create a graph for the situation. Tell whether the graph is
continuous or discrete.
The table shows
the distance traveled
during a family vacation.
Distance Travelled
Example 2A
Since every value of
time has a
corresponding altitude,
connect the points.
The graph is continuous.
Time 8:00 10:00 12:00 2:00
Distance (mi) 280 320 500 580
0
100
200
300
400
500
600
700
8:00 10:00 12:00 2:00
Time
Distance(mi)

16. Lesson Quiz
Tell which graph corresponds to the situation. Then tell
whether the graph is continuous or discrete.
A bus pulls out from the gas station. It drives to its first stop.
Then the bus gets on the expressway.
Graph B; continuous

17. 1. Maggi has $25 in her bank account. She gets $5 every day
from her father and deposits the money in the account for
the first three days. On the fourth day, she buys a hat for
herself with the money. Identify the table that
corresponds to this situation.
A. B.
Lesson Quiz for Student Response Systems

18. Discrete & Continuous Domains
Holt Course 3 3.3
Glencoe 2-3C