Pick any test to determine convergence

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    Convergence Test
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Homework Statement


Use any method or test to see if the series converges or diverges.


Homework Equations



The series:
((1/n) - (1/n^2))^n

The Attempt at a Solution


Well the integral test won't work because there's no real integral for that according to Wolfram Alpha. Also if you try the limit comparison test, the first thing is to determine where the function goes if n goes to ∞, but when it does, you get something like (0)^∞. What other test can I use?

Thanks.
 
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Hip2dagame said:

Homework Statement


Use any method or test to see if the series converges or diverges.

Homework Equations



The series:
((1/n) - (1/n^2))^n

The Attempt at a Solution


Well the integral test won't work because there's no real integral for that according to Wolfram Alpha. Also if you try the limit comparison test, the first thing is to determine where the function goes if n goes to ∞, but when it does, you get something like (0)^∞. What other test can I use?

Thanks.

Actually, the series would be the sum of those terms. I would start by writing it as$$
a_n =\left(\frac {n-1}{n^2}\right)^n$$So, thinking intuitively, for large ##n##, that ##-1## in the numerator isn't going to matte much so ##a_n## is sort of like$$
\left(\frac {1}{n}\right)^n$$Does that give you any comparison test ideas?
 
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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