To differentiate the function \( f(x) = 8 \ln x \), we will use the chain rule. The derivative of \( \ln x \) is \( \frac{1}{x} \). Therefore, the derivative of \( 8 \ln x \) is \( 8 \) times the derivative of \( \ln x \).
Step 1: Differentiate the Function
We start with the function \( f(x) = 8 \ln x \). To find the derivative \( f'(x) \), we apply the derivative rule for logarithmic functions. The derivative of \( \ln x \) is \( \frac{1}{x} \).
Step 2: Apply the Derivative Rule
Using the derivative rule, we have:
\[
f'(x) = 8 \cdot \frac{d}{dx}(\ln x) = 8 \cdot \frac{1}{x}
\]
Step 3: Simplify the Expression
Thus, the derivative simplifies to:
\[
f'(x) = \frac{8}{x}
\]
Final Answer
The derivative of the function is given by:
\[
\boxed{f'(x) = \frac{8}{x}}
\]