Posted by sarah on .
determine whether the series is convergent if so find sum
it is the sum from k=1 to infinity of ((1)^k)/(3^(k+1))
i found this series to be geometric where
a=1/9 and
r=1/3
my answer was converges to 1/6

calculus 
Damon,
(1)^k

3^(k+1)
1/9 , 1/27 , 1/3^4 ...
yes, g = 1/9
no r = 1/3 (disagree with your sign)
Sum = (1/9 ) / (1 +1/3) =1/12