If r = 2,
Sn = a*(2^(n-1)-1)
so, if b = a, it could be a gp
a,2a,4a,8a,...2^(n-1)*a
Sn = a(1+2+...+2^(n-1))
= a(2^n-1) = a*2^n-a
the sum of n terms of a series is a.2^n-b, find its n th term. are the term s of this series in g.p.?
2 answers
Maths ka solution