Hi I have a few problems with regard to infinite series and sequences: 1.) cos(n) / (n^2) summation from n = 0 to infinity 2.) cos(pi*n)/n summation from n = 0 to infinity 3.) sin(n) summation from 0 to infinity I have to tell whether they absolutely converge, conditionally converge, or diverge. I tried using the ration/root/limit test for them but nothing seemed to help. any feedback will be greatly appreciated.