How Do You Prove the Limit of (2n+1)/(n+1) as n Approaches Infinity?

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Homework Help Overview

The discussion revolves around proving the limit of the expression (2n+1)/(n+1) as n approaches infinity, specifically focusing on the application of the epsilon-delta definition of limits in calculus.

Discussion Character

  • Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants explore the correct formulation of the limit definition and question the validity of manipulating absolute values in their expressions. There is an emphasis on ensuring the correct setup for applying the limit definition.

Discussion Status

Some participants have provided guidance on the proper form of the limit expression to use, while others are seeking clarification on specific steps in their reasoning. Multiple interpretations of the limit proof are being discussed, particularly regarding the handling of absolute values.

Contextual Notes

Participants are working under the constraints of formal definitions in calculus and are attempting to adhere to the epsilon-delta framework for limits. There is an ongoing discussion about the correctness of certain mathematical manipulations.

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Prove that the limit when x--> infinite of (2n+1)/(n+1) =2
So for ε > 0,exists N>0 so that n>N => |x -a|< ε
What I do is | (2n+1)/(n+1) |< ε, I do the math actions and I have |-1/(n+1)| < ε... NOW,what I don't get,when I remove the absolute value,do I get 1/(n+1)<ε or NOT?
 
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I believe you want to use this definition :

[itex]\forall \epsilon>0, \exists N | n>N \Rightarrow |a_n - L| < \epsilon[/itex]

So what is [itex]|a_n - L|[/itex]? Plug in your info and start massaging it into a suitable expression.
 
I know what to do,I just want to know if the part when I remove the absolute value is correct :)
 
Elaia06 said:
Prove that the limit when x--> infinite of (2n+1)/(n+1) =2
So for ε > 0,exists N>0 so that n>N => |x -a|< ε
What I do is | (2n+1)/(n+1) |< ε,
This is incorrect. You should start with
|(2n + 1)/(n + 1) - 2| < ε

It looks like the above is what you were working with, but didn't write it correctly.
Elaia06 said:
I do the math actions and I have |-1/(n+1)| < ε... NOW,what I don't get,when I remove the absolute value,do I get 1/(n+1)<ε or NOT?
Yes.
Elaia06 said:
I know what to do,I just want to know if the part when I remove the absolute value is correct :)
 

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