Identify Functions

In which of the relations represented by the tables below is the output a function of the input?

Select all that apply:

[tex]\[
\begin{tabular}{c|cccc}
Input & -2 & 9 & -5 & 9 \\
\hline
Output & 7 & 0 & 9 & 3
\end{tabular}
\][/tex]

[tex]\[
\begin{tabular}{c|cccc}
Input & -5 & 8 & -2 & 2 \\
\hline
Output & 3 & 0 & -4 & -4
\end{tabular}
\][/tex]

[tex]\[
\begin{tabular}{c|cccc}
Input & -4 & -2 & 3 & 6 \\
\hline
Output & 6 & 5 & 6 & 8
\end{tabular}
\][/tex]

[tex]\[
\begin{tabular}{c|cccc}
Input & -2 & 9 & -4 & 9 \\
\hline
Output & \quad & \quad & \quad & \quad
\end{tabular}
\][/tex]



Answer :

To determine which relations represent a function, we need to check if each input value maps to only one unique output value. Here are the detailed steps and results for each of the provided tables:

First table:
[tex]\[ \begin{tabular}{c|cccc} Input & -2 & 9 & -5 & 9 \\ \hline Output & 7 & 0 & 9 & 3 \\ \end{tabular} \][/tex]

- Input [tex]\(-2\)[/tex] maps to output [tex]\(7\)[/tex].
- Input [tex]\(9\)[/tex] maps to output [tex]\(0\)[/tex].
- Input [tex]\(-5\)[/tex] maps to output [tex]\(9\)[/tex].
- Input [tex]\(9\)[/tex] maps to output [tex]\(3\)[/tex].

In this table, the input [tex]\(9\)[/tex] maps to two different outputs, [tex]\(0\)[/tex] and [tex]\(3\)[/tex]. Therefore, this relation is not a function.

Second table:
[tex]\[ \begin{tabular}{c|cccc} Input & -5 & 8 & -2 & 2 \\ \hline Output & 3 & 0 & -4 & -4 \\ \end{tabular} \][/tex]

- Input [tex]\(-5\)[/tex] maps to output [tex]\(3\)[/tex].
- Input [tex]\(8\)[/tex] maps to output [tex]\(0\)[/tex].
- Input [tex]\(-2\)[/tex] maps to output [tex]\(-4\)[/tex].
- Input [tex]\(2\)[/tex] maps to output [tex]\(-4\)[/tex].

In this table, each input maps to a unique output. Therefore, this relation is a function.

Third table:
[tex]\[ \begin{tabular}{c|cccc} Input & -4 & -2 & 3 & 6 \\ \hline Output & 6 & 5 & 6 & 8 \\ \end{tabular} \][/tex]

- Input [tex]\(-4\)[/tex] maps to output [tex]\(6\)[/tex].
- Input [tex]\(-2\)[/tex] maps to output [tex]\(5\)[/tex].
- Input [tex]\(3\)[/tex] maps to output [tex]\(6\)[/tex].
- Input [tex]\(6\)[/tex] maps to output [tex]\(8\)[/tex].

In this table, each input maps to a unique output. Therefore, this relation is a function.

Conclusion:

Based on the analysis, the relations that are functions are:

1. [tex]\[ \begin{tabular}{c|cccc} Input & -5 & 8 & -2 & 2 \\ \hline Output & 3 & 0 & -4 & -4 \\ \end{tabular} \][/tex]

2. [tex]\[ \begin{tabular}{c|cccc} Input & -4 & -2 & 3 & 6 \\ \hline Output & 6 & 5 & 6 & 8 \\ \end{tabular} \][/tex]

Hence, the correct selections are the second and third tables.