Find the best solutions to your problems with the help of IDNLearn.com's expert users. Discover detailed and accurate answers to your questions from our knowledgeable and dedicated community members.

Which function represents the reflection over the [tex]$x$[/tex]-axis of [tex]$f(x)=\sqrt{x}$[/tex]?

A. [tex]\( f(x) = -\sqrt{x} \)[/tex]

B. [tex]\[
\begin{tabular}{|c|c|}
\hline
$x$ & $y$ \\
\hline
0 & 0 \\
\hline
1 & -1 \\
\hline
2 & -1.41 \\
\hline
4 & -2 \\
\hline
\end{tabular}
\][/tex]

C. [tex]\( f(x) = -\sqrt{-x} \)[/tex]

D. [tex]\[
\begin{tabular}{|c|c|}
\hline
$x$ & $y$ \\
\hline
0 & 0 \\
\hline
-1 & -1 \\
\hline
-2 & -1.41 \\
\hline
-4 & -2 \\
\hline
\end{tabular}
\][/tex]


Sagot :

To find the function representing the reflection of [tex]\( f(x) = \sqrt{x} \)[/tex] over the [tex]\( x \)[/tex]-axis, we need to understand what reflection over the [tex]\( x \)[/tex]-axis implies. A reflection over the [tex]\( x \)[/tex]-axis transforms a point [tex]\((x, y)\)[/tex] into [tex]\((x, -y)\)[/tex]. Essentially, you are flipping the graph upside down.

Given the function [tex]\( f(x) = \sqrt{x} \)[/tex], reflecting it over the [tex]\( x \)[/tex]-axis would result in:

[tex]\[ -f(x) = -\sqrt{x} \][/tex]

Now let's verify if this transformation matches the given table values after reflection:

For [tex]\( f(x) = \sqrt{x} \)[/tex]:
- When [tex]\( x = 0 \)[/tex], [tex]\( y = \sqrt{0} = 0 \)[/tex]
- When [tex]\( x = 1 \)[/tex], [tex]\( y = \sqrt{1} = 1 \)[/tex]
- When [tex]\( x = 2 \)[/tex], [tex]\( y = \sqrt{2} \approx 1.41 \)[/tex]
- When [tex]\( x = 4 \)[/tex], [tex]\( y = \sqrt{4} = 2 \)[/tex]

After reflecting these points over the [tex]\( x \)[/tex]-axis:
- When [tex]\( x = 0 \)[/tex], [tex]\( -y = -0 = 0 \)[/tex]
- When [tex]\( x = 1 \)[/tex], [tex]\( -y = -1 \)[/tex]
- When [tex]\( x = 2 \)[/tex], [tex]\( -y = -1.41 \)[/tex]
- When [tex]\( x = 4 \)[/tex], [tex]\( -y = -2 \)[/tex]

Let’s compare these values with the values in the second table:
\begin{table}[ht]
\centering
\begin{tabular}{|c|c|}
\hline
[tex]\(x\)[/tex] & [tex]\(y\)[/tex] \\
\hline
0 & 0 \\
\hline
1 & -1 \\
\hline
2 & -1.41 \\
\hline
4 & -2 \\
\hline
\end{tabular}
\end{table}

We see that the [tex]\( y \)[/tex]-values from the reflected function [tex]\( -\sqrt{x} \)[/tex] match the values in this table exactly. Therefore, the function representing the reflection over the [tex]\( x \)[/tex]-axis of [tex]\( f(x) = \sqrt{x} \)[/tex] is:

[tex]\[ g(x) = -\sqrt{x} \][/tex]