Questions: Find the critical numbers of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.)
f(x)=5 x ln x
x=
Transcript text: Find the critical numbers of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.)
\[
\begin{array}{l}
f(x)=5 x \ln x \\
x=\square
\end{array}
\]
Solution
Solution Steps
To find the critical numbers of the function \( f(x) = 5x \ln x \), we need to find the derivative of the function and set it equal to zero. Critical numbers occur where the derivative is zero or undefined. We will solve for \( x \) to find these points.
Step 1: Find the Derivative
We start with the function \( f(x) = 5x \ln x \). To find the critical numbers, we first compute the derivative of the function:
\[
f'(x) = 5 \ln x + 5
\]
Step 2: Set the Derivative to Zero
Next, we set the derivative equal to zero to find the critical points:
\[
5 \ln x + 5 = 0
\]
This simplifies to:
\[
\ln x = -1
\]
Step 3: Solve for \( x \)
To solve for \( x \), we exponentiate both sides:
\[
x = e^{-1}
\]
This can also be expressed as:
\[
x = \frac{1}{e}
\]
Final Answer
The critical number of the function is \\(\boxed{\frac{1}{e}}\\).