Hi I have a few problems with regard to infinite series and sequences:(adsbygoogle = window.adsbygoogle || []).push({});

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.

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# Infinite series/sequences

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