How could I evaluate this IMPROPER integra?

1. Nov 3, 2007

frasifrasi

Int from 1 to infinity of ln(X)/x^(3)

--> Any ideas on how to get started(mainly the technique)? thank you.

2. Nov 3, 2007

Dick

You would first find an indefinite integral using integration by parts.

3. Nov 4, 2007

benjyk

Let u = ln x and dv/dx = x^-3 and use integration by parts.
And see what happens as the upper bound of the integral tends to infinity.