Prove the lim n→∞ (1^1+2^2+3^3+....+(n−1)^(n−1)+n^n)/(n^n)=1.

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Discussion Overview

The discussion revolves around the limit of the sum of powers divided by the highest power as n approaches infinity. Participants explore whether this limit can be evaluated using Riemann sums, focusing on the mathematical reasoning behind the expression.

Discussion Character

  • Exploratory, Mathematical reasoning

Main Points Raised

  • One participant presents the limit to be proven: $$\lim_{{n}\to{\infty}}\frac{1^1+2^2+3^3+...+(n-1)^{n-1}+n^n}{n^n} = 1.$$
  • Another participant suggests that the limit might be approached through Riemann sums, indicating a potential method for evaluation.
  • A later reply reiterates the suggestion to explore Riemann sums for finding the limit, providing a link to a related discussion on a different forum.

Areas of Agreement / Disagreement

Participants have not reached a consensus on the method for proving the limit, and multiple approaches, including the use of Riemann sums, are being considered.

Contextual Notes

The discussion does not clarify the assumptions or definitions necessary for evaluating the limit, nor does it resolve the mathematical steps involved in the proposed approaches.

lfdahl
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Prove

$$\lim_{{n}\to{\infty}}\frac{1^1+2^2+3^3+...+(n-1)^{n-1}+n^n}{n^n} = 1.$$
 
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Call the limit $\ell$. Obviously $1 \leqslant \ell $. For any $n,k \in \mathbb{N}\setminus\left\{0\right\}$ s.t. $k \leqslant n$ we have $k^k \leqslant n^k$, so we have:

$\displaystyle 1 \leqslant \ell \leqslant \lim_{{n}\to{\infty}}\frac{n^1+n^2+n^3+...+(n-1)^{n-1}+n^n}{n^n} = \lim_{n \to \infty} \frac{1}{n^n} \cdot \frac{n^{n+1}-n}{n-1} =\lim_{n \to \infty} \frac{1- {1}/{n^{n}}}{1-1/n} = 1. $

Thus $\ell = 1$. (First equality is geometric series). I'd love to know if it can be done via Riemann sums.
 
Last edited:
June29 said:
Call the limit $\ell$. Obviously $1 \leqslant \ell $. For any $n,k \in \mathbb{N}\setminus\left\{0\right\}$ s.t. $k \leqslant n$ we have $k^k \leqslant n^k$, so we have:

$\displaystyle 1 \leqslant \ell \leqslant \lim_{{n}\to{\infty}}\frac{n^1+n^2+n^3+...+(n-1)^{n-1}+n^n}{n^n} = \lim_{n \to \infty} \frac{1}{n^n} \cdot \frac{n^{n+1}-n}{n-1} =\lim_{n \to \infty} \frac{1- {1}/{n^{n}}}{1-1/n} = 1. $

Thus $\ell = 1$. (First equality is geometric series). I'd love to know if it can be done via Riemann sums.
Thankyou, June29, for your participation. Well done!(Nod)

Maybe, we should continue this thread, and ask in the forum, if the limit can be found by means of Riemanns sums?
 
lfdahl said:
Thankyou, June29, for your participation. Well done!(Nod)

Maybe, we should continue this thread, and ask in the forum, if the limit can be found by means of Riemanns sums?

Thanks. I've finally got around to ask that question.

See https://mathhelpboards.com/calculus-10/sum-powers-limit-via-riemann-sums-23664.html
 

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