I am not sure where to start. I tried u substitution, but it didn't seem to get me anywhere. This is to evaluate an infinite series using the integral test. I could use a hint. TIA.
You say you "tried u substitution" but don't say what substitution. Was it "u= ln(x)"? That would seem the obvious substitution. Of course then so the integral becomes .
And are you saying "it didn't seem to get me anywhere" because of that "x" still in the integrand? Well, if u= ln(x), then so the integral becomes
which can be integrated "by parts".