# Ln x dx

by PrudensOptimus
Tags: None
 P: 640 Integrat Ln[x]dx!!!!
 P: 333 Consider it as 1*ln(x) and use parts.
 P: 45 If you don't feel like doing it, you can always use: The Integrator It gives the answer: $$-x + x \ln x$$
P: 661

## Ln x dx

Is [x] greatest integer function??
 P: 333 Hmm, didn't consider that. I'm not sure there'd be a closed form expression for $\int ln[x] dx$ where $[x]$ is the next greatest integer function. It'd be easy enough to get a numerical answer if the interval was specified though.
 P: 22 You could break the integral into a summation. [x] is constant between intervals of integers, so you end up with a sum of trivial integrals. I think this is what Lonewolf is proposing (please excuse my ignorance!) Regards, Sam