Question

determine the sum of the following series

Answer 1

\[\Sigma \frac{ (-3)^{n-1} }{ 8^{n} }\]

Answer 2

from n=1 to infinity

Answer 3

the first few terms are

1/8, -3/64, 9/512, -27/4096

the common ratio is r = -3/8

since -1<r<1 then the series has a limiting sum

so use

\[S_{\infty} = \frac{a}{1 - r}\]

Answer 4

oaky I should be able to take it from there. :) Thanks!