\begin{tabular}{|c|c|}
\hline
[tex]$x$[/tex] & [tex]$f(x)$[/tex] \\
\hline
-4 & -6 \\
\hline
-3 & -4 \\
\hline
-2 & -1 \\
\hline
-1 & -2 \\
\hline
0 & -5 \\
\hline
1 & -8 \\
\hline
2 & -16 \\
\hline
\end{tabular}

Which is a possible turning point for the continuous function [tex]$f(x)$[/tex]?

A. [tex]$(-3, -4)$[/tex]
B. [tex]$(-2, -1)$[/tex]
C. [tex]$(0, -5)$[/tex]
D. [tex]$(1, -8)$[/tex]



Answer :

To determine which of the given points could be a turning point for the continuous function [tex]\( f(x) \)[/tex], we need to analyze the behavior of the function around each point. A turning point is where the function changes its direction, which means the slope of the function (or the derivative) changes sign. In other words, at a turning point, the slope of [tex]\( f(x) \)[/tex] changes from positive to negative or vice versa.

Let us examine the function data step-by-step:

Given data points:

[tex]\[ \begin{array}{|c|c|} \hline x & f(x) \\ \hline -4 & -6 \\ \hline -3 & -4 \\ \hline -2 & -1 \\ \hline -1 & -2 \\ \hline 0 & -5 \\ \hline 1 & -8 \\ \hline 2 & -16 \\ \hline \end{array} \][/tex]

1. Compute the differences [tex]\( \Delta f(x) \)[/tex] between consecutive points to analyze the slope:

[tex]\[ \begin{aligned} \Delta f(x_{-3}) &= f(-3) - f(-4) = -4 - (-6) = 2 \\ \Delta f(x_{-2}) &= f(-2) - f(-3) = -1 - (-4) = 3 \\ \Delta f(x_{-1}) &= f(-1) - f(-2) = -2 - (-1) = -1 \\ \Delta f(x_{0}) &= f(0) - f(-1) = -5 - (-2) = -3 \\ \Delta f(x_{1}) &= f(1) - f(0) = -8 - (-5) = -3 \\ \Delta f(x_{2}) &= f(2) - f(1) = -16 - (-8) = -8 \\ \end{aligned} \][/tex]

2. Identify where the change in sign occurs between consecutive differences:

[tex]\[ \begin{aligned} \Delta f(x_{-3}) \quad & 2 \\ \Delta f(x_{-2}) \quad & 3 \quad (\text{positive}) \\ \Delta f(x_{-1}) \quad & -1 \quad (\text{negative}) \\ \Delta f(x_{0}) \quad & -3 \\ \Delta f(x_{1}) \quad & -3 \\ \Delta f(x_{2}) \quad & -8 \\ \end{aligned} \][/tex]

We see that [tex]\(\Delta f(x_{-2})\)[/tex] is positive, and [tex]\(\Delta f(x_{-1})\)[/tex] is negative. Hence, the change from positive to negative occurs between [tex]\( x = -2 \)[/tex] and [tex]\( x = -1 \)[/tex].

Given the candidates for possible turning points:
[tex]\[ (-3, -4), (-2, -1), (0, -5), (1, -8) \][/tex]

Given that the slope change occurs around [tex]\( x = -2 \)[/tex], the possible turning point must be at [tex]\( x = -2 \)[/tex].

Thus, the possible turning point is:
[tex]\[ (-2, -1) \][/tex]