The formula for the sum of the first displaystyle n n terms of a geometric sequence is represented as displaystyle S_ nfrac a_ 1left 1- r nright 1-rtext rne text 1 S. The geometric progression can be written as. A geometric series is the sum of the numbers in a geometric progression.
The nth term of a GP series is T n ar n-1 where a first term and r common ratio T n T n-1.
Given First term a 10. For example the sequence 1 3 9 27 81 is a geometric sequence. Common ratio r 3. The formula applied to calculate sum of first n terms of a GP.
