Convergence or Divergence of a Series with Multiplication Terms?

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SUMMARY

The forum discussion revolves around the convergence or divergence of the series defined by the summation \(\sum\frac{1*3*5 ... (2k-1)}{1*4*7 ... (3k-2)}\) from \(k=1\) to infinity. Participants clarify that this series is indeed a summation involving products, despite initial confusion regarding its format. The Ratio Test is recommended as an effective method to determine the convergence of the series, with emphasis on evaluating the limit of the terms as \(k\) approaches infinity.

PREREQUISITES
  • Understanding of summation notation, specifically the use of \(\Sigma\).
  • Familiarity with series convergence concepts, including the Ratio Test.
  • Basic knowledge of calculus, particularly limits and sequences.
  • Experience with product notation in mathematical series.
NEXT STEPS
  • Study the Ratio Test for series convergence in detail.
  • Review the properties of infinite series and their convergence criteria.
  • Explore examples of series involving products to gain a better understanding.
  • Investigate the application of limits in determining the behavior of sequences.
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Mathematics students, educators, and anyone interested in series convergence, particularly those studying calculus or advanced mathematical analysis.

fiziksfun
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\sum\frac{1*3*5 ... (2k-1)}{1*4*7 ... (3k-2)}

from k=1 to infinity

Does this series converge or diverge??

I have no idea where to begin, I don't understand it's format. Aren't series usually A+B+C ... but this is just multiplication ?!

? So ?? HELP!
 
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Aren't series usually A+B+C ... but this is just multiplication ?!

It is a summation...maybe? You have indicated SOMETHING by using \Sigma. However, your use of it is vague enough that I cannot tell whether you mean to sum say 1 + 1*3/1*4 + 3*5/4*7 + etc... or the entire thing is just one term.
 
fiziksfun said:
\sum\frac{1*3*5 ... (2k-1)}{1*4*7 ... (3k-2)}

from k=1 to infinity

Does this series converge or diverge??

I have no idea where to begin, I don't understand it's format. Aren't series usually A+B+C ... but this is just multiplication ?!

? So ?? HELP!
Are you saying you don't know what "\sum" means? Obviously this IS a sum. Each of the "A", "B", and "C" being summed involves a product.

Do you remember a very simple theorem about when a sum does not converge?
 
Does it diverge because the lim as k approaches infinity is 2/3 ?
 
I recall having had something similar in Calculus II. Have you tried Ratio test? It's probably more approachable that way.
 
fiziksfun said:
Does it diverge because the lim as k approaches infinity is 2/3 ?

No. The limit of the terms is NOT 2/3. Use the ratio test as JinM suggested.
 
Is the limit 1?
 
fiziksfun said:
Is the limit 1?

Don't make wild guesses. You aren't learning anything that way. All the question is asking is for convergence/divergence of the sum. Use the ratio test.
 

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