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Mathematics 22 Online
OpenStudy (kira_yamato):

Find the following: \[\sum_{n=10}^{20}n^r\]

OpenStudy (anonymous):

what is r?

OpenStudy (unklerhaukus):

\[=10^r+11^r+12^r+13^r+14^r+15^r+16^r+17^r+18^r+19^r+20^r\]

OpenStudy (kira_yamato):

@FFM r is just a constant. @UnkleRhaukus is there a certain algebraic expression to say this long stretch of numbers?

OpenStudy (anonymous):

Kira to answer your second quotient quotient "NO".

OpenStudy (kira_yamato):

Quotient quotient? But anyways, thanks you...

OpenStudy (anonymous):

question.*

OpenStudy (anonymous):

There could be an expression using HarmonicNumber, do you want that? If yes then you might consider reading about it.

OpenStudy (unklerhaukus):

well you could write it as a sum , but that is the original expression in the question

OpenStudy (blockcolder):

If I remember correctly, there's an expression that can be used for any integer r. It has to do with Bernoulli numbers.

OpenStudy (anonymous):

@blockcolder Do you mean Faulhaber's formula ? http://en.wikipedia.org/wiki/Faulhaber's_formula

OpenStudy (blockcolder):

Yeah, that one. In this case, you need to get \(\Large \sum_{n=1}^{20}n^r-\sum_{n=1}^{10}n^r\) to get the desired sum.

OpenStudy (kira_yamato):

Thank you... ありがとうございます!!

OpenStudy (blockcolder):

Douitashimapellete. (Not sure with spelling lol)

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