Sun of the first n terms of a the series
12+2.22+32+2.42+52+2.62.... is n(n+1)2/2 when n is even
what is the sum when n is odd?
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1 Answers
Abhishek Priyam
·2009-03-26 06:14:28
if n is odd...
then sum ti n+1 terms= (n+1)(n+2)2/2
sum to n(odd) terms=(n+1)(n+2)2/2-2(n+1)2
=n2(n+1)/2