How do you find the sum of the infinite geometric series Sigma 2(2/3)^n from n=0 to oo?

1 Answer
Apr 27, 2018

sum2(2/3)^n = 6

Explanation:

sum2(2/3)^n for n=0 to infinity

=2(sum(2/3)^n)

Sum of an infinite geometric series (where the ratio r is -1<=r<=1) is given by a/(1-r) where r is the common ratio and ‘a’ is the first term.

Therefore,
sum(2/3)^n = 1/(1-(2/3))

=1/(1/3) = 3

Substituting this value in our original equation gives us -

2(sum(2/3)^n) = 2*3 = 6