How do you find the sum of (2)i1 from i=1 to 12?

1 Answer
Feb 19, 2017

The sum will equal -1365. How you get this is shown below...

Explanation:

This is a geometric series with a common ratio of -2 and a first term equal to 1 since (2)11=(2)0=1

So, the sum of n terms is given by

Sn=a1(1rn)1r

Here, n = 12 if we want the sum of the first 12 terms, so

S12=1(1(2)12)1(2)

=140963=40953=1365