Motivate integral test. Add second hint. Add second solution

Would it be possible to motivate why the integral test is a good choice here?

Please add a second hint for the substitution.

Please add a second solution for the substitution u=ln(x).

Finally, could we please not use the abusive notation with the \infty at the upper bound, but use \lim_{R \to \infty} \int_3^R instead?

So picky =p

Okay should be good now (PS. your corrections were all valid and correct)

Good job, thank you!