1. ## Int (lnx)/x^2

Integrate (lnx)/(x^2) dx

(Part of a question to determine convergence or divergence)

2. Originally Posted by jlmills5
Integrate (lnx)/(x^2) dx

(Part of a question to determine convergence or divergence)
Try integration by parts with

$\displaystyle u=\ln{x}$ and

$\displaystyle dv=\frac{1}{x^2}dx$

3. Ah, I see what I did...or rather wasn't doing. I used parts like you said but apparently was not simplifying the answer the way the key does. Thanks.

4. I need to find the limit as b -> infinity for [-(lnx+1)/x] from 1 to b.

How do I do this...do I use L'Hopital's rule for the infinity portion? I'm getting -1 as the answer but this isn't right. Any suggestions?

5. Originally Posted by jlmills5
I need to find the limit as b -> infinity for [-(lnx+1)/x] from 1 to b.

How do I do this...do I use L'Hopital's rule for the infinity portion? I'm getting -1 as the answer but this isn't right. Any suggestions?
should be +1. check your signs.