In an ap of which is the first term if the sum of first P term is zero then sum of of next Q terms

+2 votes
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asked Jun 12, 2017 in Mathematics by Riya (403 points) 1 9 28

1 Answer

+1 vote
answered Jun 12, 2017 by sarthaks (25,122 points) 9 25 41
 
Best answer

We have sum of p terms i. e.
Sp = p/2 (2a+(n-1)d)=0
or d=-2a/(n-1)d
also
Sum of next q terms means (Sum of p+q terms) - ( sum of p terms)

or sum of p+q terms because sum of p terms is 0

=> p+q/2 ( 2a +(n-1)d)
=> p+q/2 (2a + (n-1)(-2a/(n-1)d)
or
=> -a (p+q)q/p-1

Therefore, sum of the next q terms is given by

Sp+q-Sp = -a (p+q)q/p-1

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