Which table represents an exponential function of the form [tex]\( y = b^x \)[/tex] when [tex]\( 0 \ \textless \ b \ \textless \ 1 \)[/tex]?

[tex]\[
\begin{tabular}{|c|c|}
\hline
x & y \\
\hline
-3 & \frac{1}{27} \\
\hline
-2 & \frac{1}{9} \\
\hline
-1 & \frac{1}{3} \\
\hline
0 & 1 \\
\hline
1 & 3 \\
\hline
2 & 9 \\
\hline
3 & 27 \\
\hline
\end{tabular}
\][/tex]

[tex]\[
\begin{tabular}{|c|c|}
\hline
x & y \\
\hline
-3 & 27 \\
\hline
-2 & 9 \\
\hline
-1 & 3 \\
\hline
0 & 1 \\
\hline
1 & \frac{1}{3} \\
\hline
2 & \frac{1}{9} \\
\hline
3 & \frac{1}{27} \\
\hline
\end{tabular}
\][/tex]



Answer :

To determine which table represents an exponential function of the form [tex]\( y = b^x \)[/tex] with [tex]\( 0 < b < 1 \)[/tex], let's analyze each table carefully.

### First Table Analysis:
[tex]\[ \begin{array}{|c|c|} \hline x & y \\ \hline -3 & \frac{1}{27} \\ \hline -2 & \frac{1}{9} \\ \hline -2 & \frac{1}{3} \\ \hline 0 & 1 \\ \hline 1 & 3 \\ \hline 2 & 9 \\ \hline 3 & 27 \\ \hline \end{array} \][/tex]

- For [tex]\( x = -3 \)[/tex] to [tex]\( x = -2 \)[/tex]: [tex]\( \frac{1/9}{1/27} = 3 \)[/tex]
- For [tex]\( x = -2 \)[/tex] to [tex]\( x = 0 \)[/tex]: [tex]\( \frac{1}{1/9} = 9 \)[/tex]
- For [tex]\( x = 0 \)[/tex] to [tex]\( x = 2 \)[/tex]: [tex]\( \frac{9}{1} = 9 \)[/tex]
- For [tex]\( x = 2 \)[/tex] to [tex]\( x = 3 \)[/tex]: [tex]\( \frac{27}{9} = 3 \)[/tex]

We can see that the values don't maintain a consistent ratio, suggesting it is not an exponential function of the desired form.

### Second Table Analysis:
[tex]\[ \begin{array}{|c|c|} \hline x & y \\ \hline -3 & 27 \\ \hline -2 & 9 \\ \hline -1 & 3 \\ \hline 0 & 1 \\ \hline 1 & \frac{1}{3} \\ \hline 2 & \frac{1}{9} \\ \hline 3 & \frac{1}{27} \\ \hline \end{array} \][/tex]

- For [tex]\( x = -3 \)[/tex] to [tex]\( x = -2 \)[/tex]: [tex]\( \frac{9}{27} = \frac{1}{3} \)[/tex]
- For [tex]\( x = -2 \)[/tex] to [tex]\( x = -1 \)[/tex]: [tex]\( \frac{3}{9} = \frac{1}{3} \)[/tex]
- For [tex]\( x = -1 \)[/tex] to [tex]\( x = 0 \)[/tex]: [tex]\( \frac{1}{3} = \frac{1}{3} \)[/tex]
- For [tex]\( x = 0 \)[/tex] to [tex]\( x = 1 \)[/tex]: [tex]\( \frac{1/3}{1} = \frac{1}{3} \)[/tex]
- For [tex]\( x = 1 \)[/tex] to [tex]\( x = 2 \)[/tex]: [tex]\( \frac{1/9}{1/3} = \frac{1}{3} \)[/tex]
- For [tex]\( x = 2 \)[/tex] to [tex]\( x = 3 \)[/tex]: [tex]\( \frac{1/27}{1/9} = \frac{1}{3} \)[/tex]

Each ratio [tex]\( \frac{y_{n+1}}{y_{n}} \)[/tex] is [tex]\( \frac{1}{3} \)[/tex], which is consistent and within the range [tex]\( 0 < b < 1 \)[/tex].

Therefore, the second table represents an exponential function of the form [tex]\( y = b^x \)[/tex] with [tex]\( 0 < b < 1 \)[/tex].

The table number is [tex]\( \boxed{2} \)[/tex].