Proving Series Convergence: \sum_{n=1}^{\infty}\frac{\sqrt{n+1}-\sqrt{n}}{n}

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Homework Help Overview

The discussion revolves around proving the convergence of the series \(\sum_{n=1}^{\infty}\frac{\sqrt{n+1}-\sqrt{n}}{n}\). Participants are exploring methods to establish convergence, particularly through comparison tests.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants are considering the comparison test but are uncertain about which series to use for comparison. There is a suggestion to rationalize the numerator, leading to a transformed series. Questions arise regarding how to utilize the inequality \(\sqrt{n+1} > \sqrt{n}\) in their reasoning.

Discussion Status

The discussion is ongoing, with participants sharing their attempts and seeking further guidance on comparison series. There is no explicit consensus yet, but some productive lines of reasoning are being explored.

Contextual Notes

Participants express difficulty in identifying appropriate series for comparison, indicating a potential gap in foundational knowledge or assumptions regarding series behavior.

analysis001
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Homework Statement


Prove that the series \sum_{n=1}^{\infty}\frac{\sqrt{n+1}-\sqrt{n}}{n} converges.


The Attempt at a Solution


I think I'm going to use the comparison test but I'm having trouble coming up with a series to compare it to. Any clues would be great. Thanks!
 
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analysis001 said:

Homework Statement


Prove that the series \sum_{n=1}^{\infty}\frac{\sqrt{n+1}-\sqrt{n}}{n} converges.

The Attempt at a Solution


I think I'm going to use the comparison test but I'm having trouble coming up with a series to compare it to. Any clues would be great. Thanks!
Try rationalizing the numerator.
 
SammyS said:
Try rationalizing the numerator.

Yeah, I've gotten to that point, so as of now I have: \sum_{n=1}^{\infty}\frac{1}{n(\sqrt{n+1}+\sqrt{n})} but I'm still not sure what to compare it to.
 
analysis001 said:
Yeah, I've gotten to that point, so as of now I have: \sum_{n=1}^{\infty}\frac{1}{n(\sqrt{n+1}+\sqrt{n})} but I'm still not sure what to compare it to.
Let's see ...

## \sqrt{n+1}\ \ > \sqrt{n} ##

How can that help ?
 
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