Identifying Functions from Tables

Decide whether or not each table below could represent a function. If not, circle what you see that tells you it’s not a function.
In a function, there is exactly one y-value (or output) for each x-value (or input). If a table has more than one y-value (or output) for the same x-value (or input), it can’t represent a function.

x	y
0	3
1	2
2	5
3	6
4	5

Function or Not?

ind	dep
5	3
1	4
-3	5
3	6
2	7

Function or Not?

input	output
0	2
5	2
2	2
6	2
3	2

Function or Not?

x	y
1	0
1	1
1	2
1	3
1	4

Function or Not?

tickets	$
2	0
1	2
2	4
3	6
4	8

Function or Not?

input	output
-4	-2
-3	-1
-2	0
-1	1
0	2

Function or Not?

ind	dep
10	9
3	2
9	8
17	16
3	5

Function or Not?

C	F
-40	-40
0	32
10	50
37	98.6
100	212

Function or Not?

input	output
0	7
-1	2
4	3
8	6
-5	-8

Function or Not?

$	games
10	5
11	25
12	45
13	65
14	85

Function or Not?

x	y
8	10
6	5
4	0
6	-5
8	-10

Function or Not?

miles	minutes
0	0
1	2
2	4
3	6
4	8

Function or Not?

These materials were developed partly through support of the National Science Foundation, (awards 1042210, 1535276, 1648684, 1738598, 2031479, and 1501927). Bootstrap by the Bootstrap Community is licensed under a Creative Commons 4.0 Unported License. This license does not grant permission to run training or professional development. Offering training or professional development with materials substantially derived from Bootstrap must be approved in writing by a Bootstrap Director. Permissions beyond the scope of this license, such as to run training, may be available by contacting contact@BootstrapWorld.org.