NAME _____________________________________________ DATE __________________ PERIOD _________
Lesson 4 Reteach
Linear Functions
A function in which the graph of the solutions forms a line is called a linear function. A linear function
can be represented by an equation, a table, a set of ordered pairs, or a graph.
Example 1
Graph y = x - 2.
x
0
1
2
3
Step 1 Choose some values for x.
Use these values to make a
function table.
x-2
0-2
1-2
2-2
3-2
y
-2
-1
0
1
y
Step 2 Graph each ordered pair on a coordinate plane.
Draw a line that passes through the points.
The line is the graph of the linear function.
(x, y)
(0, -2)
(1, -1)
(2, 0)
(3, 1)
y=x-2
(3, 1)
(2, 0)
O
x
(1, -1)
(0, -2)
Exercises
Complete the function table. Then graph the function.
Copyright © The McGraw-Hill Companies, Inc. Permission is granted to reproduce for classroom use.
1. y = x + 3
x+3
x
-2
y
y
(x, y)
= +
0
x
O
1
2
Graph each function.
2. y = 3x + 2
3. y = 2 - x
y
y
O
4. y = 3x - 1
x
O
y
x
O
x
Determine whether each set of data is continuous or discrete.
5. the size of airmail packages
6. the number of boxes in an airmail shipment
Course 3 • Chapter 4 Functions
59
NAME _____________________________________________ DATE __________________ PERIOD _________
Lesson 4 Homework Practice
Linear Functions
Graph each function.
1. y = 2x
2. y = -4x
3. y = x - 4
y
y
O
x
4. y = x + 3
Copyright © The McGraw-Hill Companies, Inc. Permission is granted to reproduce for classroom use.
x
O
4
y
y
x
O
x
O
1
6. y = −
x+2
5. y = 3x + 1
y
O
y
x
7. CARPENTRY Mrs. Valdez can assemble a chair in 1 day
1
and a table in 4 days. Graph the function y = 5 - −
x
4
to determine how many of each type of furniture
Mrs. Valdez can assemble in 20 days. Is the function
continuous or discrete? Explain.
O
x
y
x
8. FITNESS A fitness center has set a goal to have
500 members. The fitness center already has 150 members
and adds an average of 25 members per month. The
function f(x) = 150 + 25x represents the membership
after x months. Graph the function to determine the
number of months it will take for the fitness center to
reach its membership goal. Is the function continuous
or discrete? Explain.
Course 3 • Chapter 4 Functions
y
x
59