What is the sum formula for this expression

In summary, the sum formula for this expression is the sum from n=1 to k of (n^c), where c is any real constant, represented by the sigma notation with the lower limit n=1, upper limit k, and the expression (n^c). This is not a power series and cannot be represented by the generating function \frac{x}{1 - x} as c must remain constant while n changes.
  • #1
bomba923
763
0
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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  • #2
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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  • #3
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
 
  • #5
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:

1. What is the sum formula for this expression?

The sum formula for an expression is a mathematical rule that allows you to find the sum of a series of numbers or terms. It is usually written as Σ (sigma) and followed by the expression to be summed. The general formula is Σn = a + (a + d) + (a + 2d) + ... + (a + (n-1)d), where n is the number of terms, a is the first term, and d is the common difference.

2. How do you find the sum formula for an arithmetic sequence?

To find the sum formula for an arithmetic sequence, you can use the formula Sn = n/2(2a + (n-1)d), where Sn is the sum of the n terms, a is the first term, and d is the common difference. Alternatively, you can use the general formula for a sum of a series, which is Sn = (n/2)(a + l), where l is the last term.

3. Is there a sum formula for a geometric sequence?

Yes, there is a sum formula for a geometric sequence, which is Sn = a(r^n - 1)/(r - 1), where Sn is the sum of the n terms, a is the first term, and r is the common ratio. This formula can also be written as Sn = a(1 - r^n)/(1 - r) if the common ratio is less than 1.

4. How do you find the sum of an infinite series?

The sum of an infinite series can be found by calculating the limit of the partial sums as the number of terms approaches infinity. This is represented by the symbol ∑∞. For example, the infinite series 1 + 1/2 + 1/4 + 1/8 + ... can be written as ∑∞ (1/2)^n, and its sum is equal to 2.

5. Can the sum formula be used for any type of series?

No, the sum formula can only be used for certain types of series, such as arithmetic and geometric series. Other types of series, such as divergent series, do not have a finite sum and cannot be calculated using a sum formula. It is important to identify the type of series before using a sum formula.

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