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

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SUMMARY

The series \(\sum_{n=1}^{\infty}\frac{\sqrt{n+1}-\sqrt{n}}{n}\) converges. The comparison test is a suitable method for proving this convergence. By rationalizing the numerator, the series can be rewritten as \(\sum_{n=1}^{\infty}\frac{1}{n(\sqrt{n+1}+\sqrt{n})}\). This transformation allows for a clearer comparison with a known convergent series.

PREREQUISITES
  • Understanding of series convergence tests, specifically the comparison test.
  • Familiarity with rationalizing expressions in calculus.
  • Knowledge of limits and asymptotic behavior of functions.
  • Basic algebraic manipulation skills.
NEXT STEPS
  • Study the comparison test for series convergence in detail.
  • Learn about rationalizing techniques in calculus.
  • Explore examples of series that converge and diverge for better understanding.
  • Investigate the behavior of \(\sqrt{n+1}+\sqrt{n}\) as \(n\) approaches infinity.
USEFUL FOR

Students studying calculus, particularly those focusing on series convergence, and educators looking for examples of applying the comparison test in mathematical proofs.

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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