# Math Help - approximation of sum of Alternating series

1. ## approximation of sum of Alternating series

someone please explain how to find the smallest integer n, that ensures that the partial sum s_n approximates the sum s of the series with error less than 0.001 in absolute value.

summation from 0 to infinity {(-1)^n/(sn)!}

2. Originally Posted by ramzouzy
someone please explain how to find the smallest integer n, that ensures that the partial sum s_n approximates the sum s of the series with error less than 0.001 in absolute value.

summation from 0 to infinity {(-1)^n/(sn)!}
$S=\sum_0^{\infty} \frac{(-1)^n}{(sn)!}$
The problem is that it is not clear what the $sn$ is supposed to be.