The four tables below show relationships in which the a values represent inputs and the y values represent the
corresponding outputs,
R
S
T
y
y
2
y
1-2
-3
-1
-5
-2
3
3
4
1
3
2
4
1
3
4
5
3
-3
3
7
3
3
3
-4
5
3
4
10
5
3
4
-5
Which table represents a relationship that is not a function?
A Q
B
R
D
Using the vertical line test, you can't have two x's with different y's, so since the last table has two 3's and two 4's in the x column, it cannot represent a function.
