What did i do wrong? Ratio and comparison test question?

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SUMMARY

The discussion centers on the convergence of the series summation of n/ln(n) from n=1 to infinity, utilizing the Ratio and Comparison tests. The user initially misapplied logarithmic properties in their calculations, specifically regarding the limit of ln(n+1)/ln(n). The correct approach involves applying the divergence test directly to evaluate the limit as n approaches infinity, confirming that the series does not converge to zero.

PREREQUISITES
  • Understanding of series convergence tests, specifically Ratio and Comparison tests.
  • Familiarity with logarithmic properties and limits.
  • Basic knowledge of calculus, particularly limits and infinite series.
  • Experience with mathematical notation and expressions.
NEXT STEPS
  • Review the Divergence Test for series convergence.
  • Study the properties of logarithms and their limits in calculus.
  • Practice applying the Ratio Test and Comparison Test on various series.
  • Explore advanced series convergence topics, such as the Integral Test.
USEFUL FOR

Students studying calculus, particularly those focusing on series convergence, as well as educators seeking to clarify the application of convergence tests in mathematical analysis.

rickyram
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Homework Statement



The summation of n/lnn from n=1 to infinity

Homework Equations



Ratio and Comparison test


The Attempt at a Solution



http://i55.tinypic.com/2jxuue.jpg

Alright so the way labeled "right way" on the picture is the right way according to the book but isn't the way I did with the ratio test right also? What did i do wrong?
 
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It is NOT true that

\frac{ln(n+1)}{ln(n)}=ln(1)
 
ln (n+1) / ln (n) isn't ln(1), in the limit or otherwise.
 
Oh man, I got to brush up on my logarithm rules... Anyway thanks for answerin my question, it has been a big help.
 
Apply the divergence test directly. take limit n->(infinity) n/lnn. I doubt that goes to zero!
 

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