Calculate the limit of $a_{n} = \frac{n^n}{(n-1)^n}$ when $n\rightarrow\infty$

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Homework Help Overview

The problem involves calculating the limit of the sequence \( a_{n} = \frac{n^n}{(n-1)^n} \) as \( n \) approaches infinity, focusing on the behavior of the expression as \( n \) increases.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss rewriting the expression in terms of logarithms and explore the limit of \( n \ln(1 - 1/n) \) as \( n \) approaches infinity. Suggestions include using series expansion and L'Hopital's Rule to evaluate the limit.

Discussion Status

The discussion is ongoing, with participants exploring different methods to approach the limit. Some have suggested using series expansions and L'Hopital's Rule, while the original poster acknowledges the helpfulness of these suggestions but indicates that they have not yet reached a conclusion.

Contextual Notes

There is a focus on the mathematical techniques available for evaluating the limit, with no consensus on the preferred method yet established.

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Homework Statement


Calculate the limit of a_{n} = \frac{n^n}{(n-1)^n} when n\rightarrow \infty, where n is an integer.


Homework Equations


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The Attempt at a Solution


a_{n} = \frac{n^n}{(n-1)^n} = \left(\frac{n}{n-1}\right)^{n} = e^{\ln\frac{n}{n-1}\right)^{n}} = e^{n\ln\frac{n}{n-1}} = e^{n\left(\ln(n)-\ln(n-1)\right)} = e^{-n\left(\ln(n-1)-\ln(n)\right)} = e^{-n\left(\ln\frac{n-1}{n}\right)} = e^{-n\left(\ln\left(1-\frac{1}{n}\right)\right)} =que?
 
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What is the limit of
n \ln(1 - 1/n)
as n \to \infty?
When you're not sure, try expanding the logarithm in a series around n = infinity.
 
For this limit--
\lim_{n \rightarrow \infty} n ln(1 - 1/n)
a simpler approach might be to use L'Hopital's Rule, with the limit rewritten as a quotient:
\lim_{n \rightarrow \infty} \frac{ln(1 - 1/n}{1/n})
 
While both suggestions do give me the end result I want, we have still not reached MacLaurin expansions, nor l'hospital's rule. Much thanks for your help, however.
 

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