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summation problem...
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sneaky
P versus NP
P versus NP

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#1
 summation problem...
i dont get it al all
Find the value of the sum.
n
E (2-5i) =
i=1


how would i do this?

PostPosted: Sat Nov 07, 2009 5:45 pm  Back to top 
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kenn4000
Yang-Mills Theory
Yang-Mills Theory

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#2
\sum_{i=1}^n (2-5i)=\sum_{i=1}^n 2 - 5\sum_{i=1}^n i= 2n-5\frac{n(n+1)}{2}

PostPosted: Sat Nov 07, 2009 7:05 pm  Back to top 
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J.Y.Choi
Poincare Conjecture
Poincare Conjecture

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#3
What does E mean? I don't think it means \sum. Is it the complete elliptic integral of the second kind?

PostPosted: Sat Nov 07, 2009 7:10 pm  Back to top 
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sneaky
P versus NP
P versus NP

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#4
i got that one now i dont get

\sum_{i=1}^{100} (5^i - 5^{i-1})

Moderator says: learn basic \LaTeX, it is easy!

PostPosted: Sat Nov 07, 2009 7:22 pm  Back to top 
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jmerry
Birch & Swinnerton Dyer
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#5
Telescoping series...

PostPosted: Sat Nov 07, 2009 7:44 pm  Back to top 
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kunny
Birch & Swinnerton Dyer
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#6
Thanks to Gauss!
\sum_{k = 1}^n (2 - 5k) = \frac {(2 - 5\cdot 1) + (2 - 5n)}{2}*n
_________________
Today's calculation of Integral Digest

PostPosted: Sun Nov 08, 2009 6:52 pm  Back to top 
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