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

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The discussion centers on proving the limit of the sum of powers divided by n raised to the power of n as n approaches infinity. Participants express interest in exploring whether Riemann sums can be used to find this limit. The limit is proposed to equal 1, and participants encourage further exploration of this mathematical concept. A link to a related thread on Riemann sums is provided for additional insights. The conversation emphasizes collaboration and deeper investigation into the limit's proof.
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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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