Originally Posted by

**jjtjp** here's the problem:

$\displaystyle \int_{7}^{\infty} \frac{\ln(x)}{x} dx$

I used substitution, letting $\displaystyle u = ln(x)$ which gave me $\displaystyle du=\frac{1}{x}dx$ and the resulting:

$\displaystyle \lim_{b\rightarrow \infty}\int_{ln(7)}^{ln(b)}{u} du$

This gave me $\displaystyle \lim_{b\rightarrow \infty}\frac{ln(b)^2}{2} - \frac{ln(7)^2}{2}$

Since infinity ends up in a numerator, I would think the answer is that the solution DNE, and it diverges, but webwork won't accept that. Where did I go wrong? Thanks MHF!!