SOLUTION: Write the following series in summation notation please? 12+6+3+1.5+0.75

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Question 1076020: Write the following series in summation notation please?
12+6+3+1.5+0.75
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
It's obviously the sum of a geometric sequence with first term 12 and common ratio 0.5=1/2.
The general expression for term number k is
12%2A%281%2F2%29%5E%28k-1%29 .
The sum of the 5 terms shown can be written as
sum%2812%2F2%5E%28k-1%29%2Ck=1%2Ck=5%29