What is the sum formula for this expression

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Discussion Overview

The discussion revolves around finding a sum formula for the expression "the sum from n=1 to k of (n^c)" where c is any real constant. Participants explore the nature of this summation, its mathematical properties, and potential representations.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant asks for the sum formula for the expression involving the sum of n raised to the power of c, where c is a real constant.
  • Another participant mentions that the resulting expression would be a (c+1)th degree polynomial in k, suggesting a general form but expressing uncertainty about the coefficients.
  • A participant shares a link to a generating function, indicating a possible connection but later clarifies that the generating function does not apply since c remains constant while n varies.
  • There is a discussion about the nature of the summation, emphasizing that c does not change and thus the expression does not fit the form of a typical power series.

Areas of Agreement / Disagreement

Participants express differing views on the applicability of generating functions and the nature of the summation. There is no consensus on a closed form for the sum or the coefficients involved.

Contextual Notes

Participants note the importance of the constant nature of c in the summation, which affects the applicability of certain mathematical tools like generating functions. There is also uncertainty regarding the coefficients in the polynomial representation.

bomba923
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What is the sum formula for this expression??

"The sum from n=1 to k of (n^c) for any real constant c"

k
sigma (n^c)
n=1


(lower limit n=1, upper limit k) for the sum (n^c), where c is any real constant
 

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Sorry, um, the text file needed mathtype to view :frown:

Um, here's a GIF gif picture format; i attached it and it will open easily (gif picture format) it's an attachment, the GIF image format formula; it will open easily i hope (whtisthsum.gif)
 

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Well it would be (c+1)th degree equation in k
so u can write it as a_(c+1)1*k^(c+1)+a_ck^c+...+a_0

I am not sure whether there is a neat closed form expression which will give u the a_i's ...

-- AI
 
Zurtex said:
http://mathworld.wolfram.com/GeneratingFunction.html

Hope that helps :smile:, looks like it is:

[tex]\frac{x}{1 - x}[/tex]

Yeah, but the n changes, whereas the 'c' stays constant...
it's not to the power of 1, then 2, then 3...but always to an unchanging constant c...only the 'n' changes as u add...

1+(2^c)+(3^c)+(4^c)+(5^c)+(6^c)+...+(k^c)...so the c can be any real value...but c remains constant! only the 'n' changes!<=as u add

That's why this is not really a power series,; the 'c' must be constant, and cannot change! (that's why the [tex]\frac{x}{1 - x}[/tex] doesn't work)!
 
Last edited:

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