To solve the indefinite integral \(\int \frac{(\ln x)^6}{x} dx\), we can use the substitution method. Let \(u = \ln x\). Then, \(du = \frac{1}{x} dx\). This transforms the integral into a simpler form that can be integrated directly.
Solution Approach
Use the substitution \(u = \ln x\), which implies \(du = \frac{1}{x} dx\).
Rewrite the integral in terms of \(u\).
Integrate the resulting expression with respect to \(u\).
Substitute back \(u = \ln x\) to get the final answer.
Step 1: Substitution
We start with the integral
\[
\int \frac{(\ln x)^6}{x} \, dx.
\]
We use the substitution \(u = \ln x\), which gives us \(du = \frac{1}{x} \, dx\). This transforms the integral into
\[
\int u^6 \, du.
\]
Step 2: Integration
Next, we integrate \(u^6\):
\[
\int u^6 \, du = \frac{u^7}{7} + C,
\]
where \(C\) is the constant of integration.
Step 3: Back Substitution
Now, we substitute back \(u = \ln x\) into our result: