Let S be the sum, P the product and R the sum of reciprocals of n terms in a G.P.

Prove that P2Rn = Sn.


Let the G.P. be a, ar, ar2, ar3, … arn - 1


According to question -




[ Sum of first n natural numbers is n(n + 1)/2]




Now,


L.H.S = P2Rn






= Sn


= R.H.S


Hence, P2Rn= Sn


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