Determining Divergence or Convergence in Series

badirishluck
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Homework Statement


\sum (2n^{2}+3n)/\sqrt{5+n^{5}}
index n=1 to infinity

Homework Equations





The Attempt at a Solution


I tried both the Ratio Test (limit as n goes to infinity of a_{n+1}/a_{n}) and the Limit comparison test (limit as n goes to infinity of a_{n}/ b_{n}) but wasn't able to come up with the same answer from the two tests. What am I doing wrong?
Does it converge or diverge? How?
 
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try breaking it into 2 pieces and see what you can do with the individual pieces, see if
\sum (2n^{2})/\sqrt{5+n^{5}}
converges, if it does then the whole thing does since the 2nd term is smaller, if it doesn't then the whole thing does not converge.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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