Absolute Convergence: Solve w/ Supercomputer in Scientific Notation

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    Absolute Convergence
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Homework Help Overview

The problem involves determining the convergence of the series from n=2 to infinity of ((-1)^(n+1))/(ln(n)), specifically whether it converges absolutely, conditionally, or diverges. Additionally, it includes a computational aspect regarding the time required for a supercomputer to estimate the sum to a specified error margin.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • The original poster attempts to use power series and relates it to derivatives and antiderivatives, expressing uncertainty about their approach and the relevance of the supercomputer aspect.
  • Some participants suggest comparing the series to 1/n and discuss bounding the tail of the series to estimate the number of terms needed for the desired accuracy.
  • Others inquire about the alternating series test and its implications for error estimation in convergent series.

Discussion Status

The discussion is exploring various interpretations of the convergence of the series and the computational question. Participants are providing guidance on bounding techniques and referencing relevant tests without reaching a consensus on the overall approach.

Contextual Notes

The original poster expresses confusion regarding the setup of the problem and the role of the supercomputer, indicating potential gaps in understanding the problem's requirements.

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Determine wheter the sum from n=2 to infinity of ((-1)^(n+1))/(ln(n)) converges absolutely, converges conditionally, or diverges. Also assume you have a supercomputer that can add 10^15 terms per second (which is very fast for even a supercomputer). If you wanted to estimate the sum to within an error of .01, how long would this take? Give your answer in years. preferably in scientific notation. In what state will you find the Earth when your computer has completed this computation? :bugeye:

When I first started trying this problem, I attempted using the Power series, as it's something we've been recently covering in class. Today we went over the derivatives and antiderivatives of functions such as this, and their relation to each other. The major place where I'm running into trouble is with the imaginary supercomputer thing. Also, I'm not sure if I'm starting in the right place? I appreciate any help received. Thanks.
 
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converges conditionally. compare with the series 1/n not sure about the part about the supercomputer
 
You should have a simple way of bounding the 'tail' of the series (as it's an alternating one). Using this bound, find out how many terms you have to add to get within the specified error.
 
In a convergent alternating series, the error is always less than the absolute value of the first term of the tail. Have you learned about the alternating series test?
 

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