Another sequence convergence proof

Click For Summary

Homework Help Overview

The discussion revolves around the convergence of the sequence defined by y_n := √(n+1) - √n for n in the natural numbers. Participants are exploring how to demonstrate that this sequence converges to 0.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to manipulate the expression |√(n+1) - √n| to show it is less than any ε > 0. Some participants suggest using a rationalization technique involving the conjugate to simplify the expression.

Discussion Status

Participants are actively engaging with the problem, with some providing suggestions for manipulation. There is a sense of progress as one participant expresses realization about the approach, while another seeks clarification on the next steps following a specific manipulation.

Contextual Notes

The original poster indicates difficulty with the size of terms during manipulation, suggesting potential constraints in their approach. The discussion does not resolve the problem but explores various methods and interpretations.

antiemptyv
Messages
31
Reaction score
0

Homework Statement



Let [tex]y_n := \sqrt{n+1} - \sqrt{n}[/tex] for [tex]n \in \mathbb{N}[/tex]. Show that [tex](y_n)[/tex] converges.

Homework Equations



The Attempt at a Solution



I see that it converges to 0. I just need a nudge in the right direction at getting into [tex]| \sqrt{n+1} - \sqrt{n} - 0 | = | \sqrt{n+1} - \sqrt{n} |[/tex] to show it's less than any [tex]\epsilon > 0[/tex]. Any manipulating I've tried so far makes the terms way too big to work with.
 
Last edited:
Physics news on Phys.org
How about

[tex]\left(\sqrt{n+1} - \sqrt{n}\right) \cdot \frac{\sqrt{n+1} + \sqrt{n}}{\sqrt{n+1} + \sqrt{n}}[/tex]
 
ohhhh, i see it now.
 
What do you do after
1/(sqrt{n+1)+sqrt{n}) ??
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K