Welcome to Westonci.ca, the ultimate question and answer platform. Get expert answers to your questions quickly and accurately. Ask your questions and receive precise answers from experienced professionals across different disciplines. Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals.

Select the correct answer.

Function [tex]\( k \)[/tex] is a continuous quadratic function that includes the ordered pairs shown in the table.

[tex]\[
\begin{tabular}{|c|c|c|c|c|c|c|}
\hline
x & -1 & 0 & 1 & 2 & 3 & 4 \\
\hline
k(x) & 5 & 8 & 9 & 8 & 5 & 0 \\
\hline
\end{tabular}
\][/tex]

Over which interval of the domain is the function increasing?

A. [tex]\((1, \infty)\)[/tex]

B. [tex]\((-\infty, \infty)\)[/tex]

C. [tex]\((-\infty, 1)\)[/tex]

D. [tex]\((-\infty, 9)\)[/tex]


Sagot :

To determine the interval where the function [tex]\( k \)[/tex] is increasing, we need to examine the values of [tex]\( k(x) \)[/tex] as [tex]\( x \)[/tex] changes. Here's a detailed analysis based on the table provided:

[tex]\[ \begin{array}{|c|c|c|c|c|c|c|} \hline x & -1 & 0 & 1 & 2 & 3 & 4 \\ \hline k(x) & 5 & 8 & 9 & 8 & 5 & 0 \\ \hline \end{array} \][/tex]

### Step-by-Step Analysis:

1. Identify Changes in [tex]\( k(x) \)[/tex]:
- From [tex]\( x = -1 \)[/tex] to [tex]\( x = 0 \)[/tex]:
- [tex]\( k(-1) = 5 \)[/tex] and [tex]\( k(0) = 8 \)[/tex]. Since [tex]\( 8 > 5 \)[/tex], [tex]\( k(x) \)[/tex] is increasing in this interval.
- From [tex]\( x = 0 \)[/tex] to [tex]\( x = 1 \)[/tex]:
- [tex]\( k(0) = 8 \)[/tex] and [tex]\( k(1) = 9 \)[/tex]. Since [tex]\( 9 > 8 \)[/tex], [tex]\( k(x) \)[/tex] is increasing in this interval.
- From [tex]\( x = 1 \)[/tex] to [tex]\( x = 2 \)[/tex]:
- [tex]\( k(1) = 9 \)[/tex] and [tex]\( k(2) = 8 \)[/tex]. Since [tex]\( 9 > 8 \)[/tex], [tex]\( k(x) \)[/tex] is decreasing in this interval.
- From [tex]\( x = 2 \)[/tex] to [tex]\( x = 3 \)[/tex]:
- [tex]\( k(2) = 8 \)[/tex] and [tex]\( k(3) = 5 \)[/tex]. Since [tex]\( 8 > 5 \)[/tex], [tex]\( k(x) \)[/tex] is decreasing in this interval.
- From [tex]\( x = 3 \)[/tex] to [tex]\( x = 4 \)[/tex]:
- [tex]\( k(3) = 5 \)[/tex] and [tex]\( k(4) = 0 \)[/tex]. Since [tex]\( 5 > 0 \)[/tex], [tex]\( k(x) \)[/tex] is decreasing in this interval.

2. Determine Intervals:
- We see that the function [tex]\( k \)[/tex] is increasing for [tex]\( x = -1 \)[/tex] to [tex]\( x = 1 \)[/tex].

### Conclusion:
The interval over which the function [tex]\( k \)[/tex] is increasing is from [tex]\( x = -1 \)[/tex] to [tex]\( x = 1 \)[/tex].

Thus, the correct answer is:
[tex]\[ \boxed{(-1, 1)} \][/tex]