Question

What is the sum of this geometric series?

1/3-1/9+1/27-1/81+...

Answer 1

formula for sum of geometric series
\[S = \frac{a(1-r^{n})}{1-r}\]
a = 1st term
r = ratio
n = num of terms

Answer 2

in this case n is infinity , i assume "..." means it goes on forever

Answer 3

a = 1/3

r = -1/3