1. For large n behave like
    1
    n
    and so like harmonic series and diverges.
  2. Using ratio test this is less that 1 and so converges.
  3. Not sure..if was n2 at the bottom then could say that converges absolutely but as things stand don't know.

    [In fact this series does converge but it's more hassle than its worth to show this. Should have asked over n2 in which case could show that it converges absolutely and we'd be done.]

File translated from TEX by TTH, version 2.70.
On 16 May 2002, 10:57.