Question

Find Sn for this geometric series.
f(1) = 1/2, r= -5, n= 6

Answer 1

well the formula for the sum of a geometric series is

\[S_{n} = \frac{a(1 - r^n)}{1 - r}\]

just substitute and then calculate.

Answer 2

The answer in the back of my book says its -1302 :(

Answer 3

well what did you get...?

so the 1st term is 1/2

so you have

\[S_{6} = \frac{1/2(1 - (-5)^6)}{1 - (-5)}\]

well if you calculate correctly, you'll get the answer in th back of the book,,