posted by Anonymous .
If S1 = 0.7 and S2 = 2.1 in geometric series, what would the sum of the first 12 terms in the series be?
I tried doing this, and I got 1.16 or something :S How exactly do I do this? Please tell me what formula to use. I was using the Sn = a(rn-1)/r-1
The geometric series up to the nth term is generally represented by the formula:
S(n)=a + ar + ar^2 + ar^3 .... + ar^(n-1)
The formula for calculating the first n terms is
You calculator should tell you that S(12) is below 3000.