Kareem wants to write an equation for the data in the table below.

\begin{tabular}{|c|c|}
\hline
[tex]$x$[/tex] & [tex]$y$[/tex] \\
\hline
-3 & [tex]$\frac{1}{8}$[/tex] \\
\hline
-2 & [tex]$\frac{1}{4}$[/tex] \\
\hline
-1 & [tex]$\frac{1}{2}$[/tex] \\
\hline
0 & 1 \\
\hline
\end{tabular}

What is the general form of the equation Kareem can use to represent the data?

A. [tex]$y = mx + b$[/tex]

B. [tex]$y = ab^x$[/tex]

C. [tex]$y = ax^2 + bx + c$[/tex]



Answer :

To determine the general form of the equation that best fits the given data points, we will analyze the data and derive the proper model.

Given data points:
- (-3, [tex]\( \frac{1}{8} \)[/tex])
- (-2, [tex]\( \frac{1}{4} \)[/tex])
- (-1, [tex]\( \frac{1}{2} \)[/tex])
- (0, 1)

We are considering the following general forms:
1. [tex]\( y = mx + b \)[/tex] - Linear equation
2. [tex]\( y = a b^x \)[/tex] - Exponential equation
3. [tex]\( y = ax^2 + bx + c \)[/tex] - Quadratic equation

First, let's observe the pattern in the given [tex]\( y \)[/tex]-values as [tex]\( x \)[/tex]-values change.

Pattern Recognition:

Transforming the [tex]\( y \)[/tex]-values into a more recognizable form by rewriting them in terms of powers of 2:
- [tex]\( \frac{1}{8} = 2^{-3} \)[/tex]
- [tex]\( \frac{1}{4} = 2^{-2} \)[/tex]
- [tex]\( \frac{1}{2} = 2^{-1} \)[/tex]
- [tex]\( 1 = 2^{0} \)[/tex]

Here, it is evident that the [tex]\( y \)[/tex]-values can be represented as [tex]\( y = 2^x \)[/tex]. This suggests an exponential relationship between [tex]\( y \)[/tex] and [tex]\( x \)[/tex].

Thus, the general form of the equation that represents the data is:

[tex]\[ y = a b^x \][/tex]

To find the constants [tex]\( a \)[/tex] and [tex]\( b \)[/tex], we consider the table and note that the form [tex]\( y = ab^x \)[/tex] matches the data perfectly if [tex]\( a = 1 \)[/tex] and [tex]\( b = 2 \)[/tex]:

- For [tex]\(x = 0, y = 1\)[/tex], which confirms [tex]\( a = 1 \)[/tex].
- For other values of [tex]\(x\)[/tex], we observe the exponential growth factor [tex]\( b = 2 \)[/tex].

So, the equation that represents the data is:

[tex]\[ y = 1 \cdot 2^x \][/tex]

Simplifying, we get:

[tex]\[ y = 2^x \][/tex]

Therefore, Kareem can use the exponential form [tex]\( y = ab^x \)[/tex] to represent the data, where [tex]\( a = 1 \)[/tex] and [tex]\( b = 2 \)[/tex]. Thus, the specific equation is [tex]\( y = 2^x \)[/tex].