The sum of a series for the first n terms is
The sum of an infinite geometric series (assuming |r|<1) is
With your information
im really stuck on this question.
The sum of the first 4 terms ofa geometric series is 30, and the sum of the infinite series is 32. Find the first 3 terms.
i know i have to find a and r, however Im not sure how to do it.
Do i work out what a is for both sides??? HELP!!!.. PLEASE