What values of z in the complex plane make the series absolutely convergent?

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Discussion Overview

The discussion centers around determining the values of \( z \) in the complex plane for which the series \( \sum (1/n!)(1/z)^n \) is absolutely convergent. The scope includes mathematical reasoning and concepts related to series convergence in complex analysis.

Discussion Character

  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant seeks assistance in identifying the set of \( z \) for which the series converges absolutely.
  • Another participant suggests substituting \( w = \frac{1}{z} \) to potentially simplify the problem.
  • A participant expresses confusion about how to approach such problems and requests a more logical explanation.
  • One reply recommends using the ratio test and emphasizes the importance of including limits in the analysis, while also noting the connection to the series for \( \exp(1/z) \).
  • A participant reflects on their learning process and expresses a desire to improve, acknowledging their struggle with the concepts.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the approach to solving the problem, with multiple perspectives on how to analyze the series and differing levels of understanding expressed.

Contextual Notes

There are indications of missing assumptions regarding the convergence criteria and the implications of the substitution suggested. The discussion does not resolve the mathematical steps necessary for determining convergence.

heman
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Hi,
In this Problem i am finding Problem to calculate the set of z:
Pls help
Determine all z [tex]\subset[/tex] C for which the following series is absolutely convergent:

[tex]\sum (1/n!)(1/z)^n[/tex]

Thx
 
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Do the terms look familiar? What if you set [itex]w=\frac{1}{z}[/itex]?
 
okay ...but generally how to solve such kind of problems..can u be more logical pls
 
Use the ratio test (and i don't think you should accuse others of not being logical. pointing out that this is the series for exp{1/z} give or take a constant is very logical. you ought to put in the limits too).
 
its just my concepts are not clear...how can i accuse anyone here..i have learned a lot from ppl here and i want to improve
Sometimes even in my class i end up asking such stupid questions that whole class bursts into laughter..
Thx for it and urs reply in pm...
 

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