Complete the equation describing how [tex]\( x \)[/tex] and [tex]\( y \)[/tex] are related.

[tex]\[
\begin{tabular}{|c|c|c|}
\hline
$x$ & $y$ & $\frac{dy}{dx}$ \\
\hline
-5 & 17 & \\
\hline
-4 & 14 & \\
\hline
-3 & 11 & \\
\hline
-2 & 8 & \\
\hline
-1 & 5 & \\
\hline
0 & 2 & \\
\hline
\end{tabular}
\][/tex]

Given the values, determine the equation for [tex]\( y \)[/tex] and find the derivative [tex]\(\frac{dy}{dx}\)[/tex].



Answer :

To complete the equation that describes how [tex]\( x \)[/tex] and [tex]\( y \)[/tex] are related given the table, we will determine the slope ([tex]\( dy/dx \)[/tex]) between consecutive values of [tex]\( x \)[/tex] and [tex]\( y \)[/tex].

The given table is:
[tex]\[ \begin{array}{|c|c|c|} \hline x & y & dy \\ \hline -5 & 17 & \\ \hline -4 & 14 & \quad=[?] x \\ \hline -3 & 11 & \\ \hline -2 & 8 & \\ \hline -1 & 5 & \\ \hline 0 & 2 & \\ \hline \end{array} \][/tex]

First, we can look at the change in [tex]\( y \)[/tex] with respect to [tex]\( x \)[/tex] for each interval:

[tex]\[ \begin{aligned} dy_1 &= \frac{y(-4) - y(-5)}{-4 - (-5)} = \frac{14 - 17}{-4 + 5} = \frac{-3}{1} = -3, \\ dy_2 &= \frac{y(-3) - y(-4)}{-3 - (-4)} = \frac{11 - 14}{-3 + 4} = \frac{-3}{1} = -3, \\ dy_3 &= \frac{y(-2) - y(-3)}{-2 - (-3)} = \frac{8 - 11}{-2 + 3} = \frac{-3}{1} = -3, \\ dy_4 &= \frac{y(-1) - y(-2)}{-1 - (-2)} = \frac{5 - 8}{-1 + 2} = \frac{-3}{1} = -3, \\ dy_5 &= \frac{y(0) - y(-1)}{0 - (-1)} = \frac{2 - 5}{0 + 1} = \frac{-3}{1} = -3. \end{aligned} \][/tex]

As can be seen from the calculations, the rate of change [tex]\( dy/dx \)[/tex] in each interval is consistently [tex]\(-3\)[/tex].

Therefore, for the row where [tex]\( x = -4 \)[/tex]:

[tex]\[ dy = -3 \times \Delta x \][/tex]

Given [tex]\(\Delta x = 1\)[/tex] (because the difference in [tex]\( x \)[/tex] values is [tex]\(-4 - (-5) = 1\)[/tex]), we can write:

[tex]\[ dy = -3 \times (-4 - (-5)) = -3 \times 1 = -3 \][/tex]

So the relation for [tex]\( dy \)[/tex] when [tex]\( x = -4 \)[/tex] is:

[tex]\[ dy = -3 \times 1 = -3 \][/tex]

Thus, for the row where [tex]\( x = -4 \)[/tex], the completed equation is:

[tex]\[ \begin{array}{|c|c|c|} \hline x & y & dy \\ \hline -5 & 17 & \\ \hline -4 & 14 & = -3 \times 1 \\ \hline -3 & 11 & \\ \hline -2 & 8 & \\ \hline -1 & 5 & \\ \hline 0 & 2 & \\ \hline \end{array} \][/tex]