All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Just Math > Calculus
Sum Exponent Ratio Evaluation (Posted on 2023-05-27) Difficulty: 3 of 5
Evaluate:
        n + n2 + n3 +...  ...+ nn
Limit  --------------------------
nā†’āˆž    1n + 2n + 3n +...  ...+ nn

See The Solution Submitted by K Sengupta    
Rating: 5.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution Got it with some help Comment 2 of 2 |
From my previous comment:
The numerator should be:
n * (n^n - 1)/(n-1)

Evaluating the denominator for different values of n leads to Sloane's oeis A031971.

And looking through the notes, there are several approximations for the value of this series.

One is:  a(n) is asymptotic to (e/(e - 1))*n^n. - Benoit Cloitre, Dec 17 2003

So taking the numerator as:    n * (n^n - 1)/(n-1)
and taking the denominator as: (e/(e - 1))*n^n

Cancel out n/(n-1)
Cancel out (n^n - 1)/n^n

And we have (e - 1)/e =~ 0.632120558828558

Which is close to my f(10,000) = 0.6322235834032078
  Posted by Larry on 2023-05-27 14:35:27
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (10)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information