# Math Help - summation notation

1. ## summation notation

Hi, I'm having trouble turning this summation notation into a function, any help would be greatly appreciated. Thank you.
(1/5)^k

2. Originally Posted by checkeredshawn
Hi, I'm having trouble turning this summation notation into a function, any help would be greatly appreciated. Thank you.
(1/5)^k
Hello,

what you describe is one value because the infinite geometric serie is convergent. The limes can be calcutated:

$s=\frac{a_1}{1-q}$.
With your problem $a_1=\frac{1}{5}\text{ and }q=\frac{1}{5}$. Plug in these values:

$s=\frac{\frac{1}{5}}{1-\frac{1}{5}}=\frac{1}{4}$.

EB