Answered

Which table represents an exponential function?

[tex]\[
\begin{tabular}{|c|c|}
\hline
$x$ & $y$ \\
\hline
1 & 5 \\
\hline
2 & 10 \\
\hline
3 & 15 \\
\hline
4 & 20 \\
\hline
5 & 25 \\
\hline
\end{tabular}
\][/tex]



Answer :

Let's determine whether the given table represents an exponential function.

An exponential function has the form [tex]\( y = a \cdot b^x \)[/tex], where [tex]\( a \)[/tex] and [tex]\( b \)[/tex] are constants, and [tex]\( b \)[/tex] (the base) is the same for each pair of successive [tex]\( x \)[/tex]-values.

Given data in the table:

[tex]\[ \begin{array}{|c|c|} \hline x & y \\ \hline 1 & 5 \\ \hline 2 & 10 \\ \hline 3 & 15 \\ \hline 4 & 20 \\ \hline 5 & 25 \\ \hline \end{array} \][/tex]

To check if this table represents an exponential function, we need to look at the ratios of successive [tex]\( y \)[/tex]-values:

1. Calculate the ratio of [tex]\( y \)[/tex]-values for [tex]\( x = 2 \)[/tex] and [tex]\( x = 1 \)[/tex]:
[tex]\[ \text{Ratio} = \frac{y(2)}{y(1)} = \frac{10}{5} = 2.0 \][/tex]

2. Calculate the ratio of [tex]\( y \)[/tex]-values for [tex]\( x = 3 \)[/tex] and [tex]\( x = 2 \)[/tex]:
[tex]\[ \text{Ratio} = \frac{y(3)}{y(2)} = \frac{15}{10} = 1.5 \][/tex]

3. Calculate the ratio of [tex]\( y \)[/tex]-values for [tex]\( x = 4 \)[/tex] and [tex]\( x = 3 \)[/tex]:
[tex]\[ \text{Ratio} = \frac{y(4)}{y(3)} = \frac{20}{15} \approx 1.333 \][/tex]

4. Calculate the ratio of [tex]\( y \)[/tex]-values for [tex]\( x = 5 \)[/tex] and [tex]\( x = 4 \)[/tex]:
[tex]\[ \text{Ratio} = \frac{y(5)}{y(4)} = \frac{25}{20} = 1.25 \][/tex]

We observe that the ratios between successive [tex]\( y \)[/tex]-values are:

[tex]\[ [2.0, 1.5, 1.333, 1.25] \][/tex]

Since these ratios are not all the same, we can conclude that the table does not represent an exponential function. For a table to represent an exponential function, the ratio of successive [tex]\( y \)[/tex]-values must be constant.

Therefore, the table does not represent an exponential function.