The table represents an exponential function.

\begin{tabular}{|c|c|}
\hline
[tex]$x$[/tex] & [tex]$y$[/tex] \\
\hline
1 & 2 \\
\hline
2 & [tex]$\frac{2}{5}$[/tex] \\
\hline
3 & [tex]$\frac{2}{25}$[/tex] \\
\hline
4 & [tex]$\frac{2}{125}$[/tex] \\
\hline
\end{tabular}

What is the multiplicative rate of change of the function?

A. [tex]$\frac{1}{5}$[/tex]
B. [tex]$\frac{2}{5}$[/tex]
C. 2
D. 5



Answer :

To determine the multiplicative rate of change for the given values in the table, let's analyze the changes in [tex]\( y \)[/tex] as [tex]\( x \)[/tex] increases.

The given values are:
- When [tex]\( x = 1 \)[/tex], [tex]\( y = 2 \)[/tex]
- When [tex]\( x = 2 \)[/tex], [tex]\( y = \frac{2}{5} \)[/tex]
- When [tex]\( x = 3 \)[/tex], [tex]\( y = \frac{2}{25} \)[/tex]
- When [tex]\( x = 4 \)[/tex], [tex]\( y = \frac{2}{125} \)[/tex]

First, we'll calculate the rate of change between each pair of consecutive [tex]\( y \)[/tex]-values.

1. From [tex]\( y_1 = 2 \)[/tex] to [tex]\( y_2 = \frac{2}{5} \)[/tex]

[tex]\[ \text{Rate of Change}_1 = \frac{\frac{2}{5}}{2} = \frac{2}{5} \times \frac{1}{2} = \frac{2}{10} = 0.2 \][/tex]

2. From [tex]\( y_2 = \frac{2}{5} \)[/tex] to [tex]\( y_3 = \frac{2}{25} \)[/tex]

[tex]\[ \text{Rate of Change}_2 = \frac{\frac{2}{25}}{\frac{2}{5}} = \frac{2}{25} \times \frac{5}{2} = \frac{10}{50} = 0.2 \][/tex]

3. From [tex]\( y_3 = \frac{2}{25} \)[/tex] to [tex]\( y_4 = \frac{2}{125} \)[/tex]

[tex]\[ \text{Rate of Change}_3 = \frac{\frac{2}{125}}{\frac{2}{25}} = \frac{2}{125} \times \frac{25}{2} = \frac{50}{250} = 0.2 \][/tex]

Since the multiplicative rate of change is consistent and equal to [tex]\( 0.2 \)[/tex], we can now return to the provided options to match this rate of change:

[tex]\[ \frac{1}{5} = 0.2, \quad \frac{2}{5} = 0.4, \quad 2 = 2.0, \quad 5 = 5.0 \][/tex]

Therefore, the multiplicative rate of change is:

[tex]\[ \boxed{\frac{1}{5}} \][/tex]