# Sum the series 1+(1+2)+(1+2+3)+...n terms.

2
by garimabhutani
what is the n term???
not given
so where would it end???????? i mean what would be the last no
dont knw dis is d ques. which i hve copied from d book.
ok

2014-12-31T21:23:24+05:30
N th term is =n(n+1)/2=n²+n/2=n²/2+n/2

submission
1/2εn²+1/2∈n=n(n+1)(2n+1)/12+n(n+1)/4

after simplyfing it equals =n(n+1)(n+2)/6
nice..
THNKS
2014-12-31T22:41:44+05:30

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In the series 1+(1+2)+(1+2+3)....., the nth term is the sum of numbers from 1 to n.
So the nth term is n(n+1)/2.
So we need to find the sum of a series whose nth term is n(n+1)/2.

any constan multiplication shuld be outside the sigma
which constant?
1/2
ur answer is correct but ur notation is wrong
okkk...