Section 2.1
Introduction to Functions
87
Version: Fall 2007
2.1
Exercises
In
Exercises 1

6
, state the domain and
range of the given relation.
1.
R
=
{
(1
,
3)
,
(2
,
4)
,
(3
,
4)
}
2.
R
=
{
(1
,
3)
,
(2
,
4)
,
(2
,
5)
}
3.
R
=
{
(1
,
4)
,
(2
,
5)
,
(2
,
6)
}
4.
R
=
{
(1
,
5)
,
(2
,
4)
,
(3
,
6)
}
5.
x
5
y
5
6.
x
5
y
5
Copyrighted material. See:
1
In
Exercises 7

12
, create a mapping di
agram for the given relation and state
whether or not it is a function.
7.
The relation in
Exercise 1
.
8.
The relation in
Exercise 2
.
9.
The relation in
Exercise 3
.
10.
The relation in
Exercise 4
.
11.
The relation in
Exercise 5
.
12.
The relation in
Exercise 6
.
13.
Given that
g
takes a real number
and doubles it, then
g
:
x
→
?
.
14.
Given that
f
takes a real number
and divides it by 3, then
f
:
x
→
?
.
15.
Given that
g
takes a real number
and adds 3 to it, then
g
:
x
→
?
.
16.
Given that
h
takes a real number
and subtracts 4 from it, then
h
:
x
→
?
.
17.
Given that
g
takes a real number,
doubles it, then adds 5, then
g
:
x
→
?
.
18.
Given that
h
takes a real number,
subtracts 3 from it, then divides the re
sult by 4, then
h
:
x
→
?
.
Given that the function
f
is defined by
the rule
f
:
x
→
3
x

5
, determine
where the input number is mapped in
Exercises 19

22
.
19.
f
: 3
→
?