I'm trying to find:
I manipulate this the following way:
Is this right? Thanks
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Yes you can derive that result directly in the same way that the general formula is derived, I just tried it myself and the peculiar common ratio in the series does not change the derivation.
I see, thanks. Now, If I want to obtain the sum from just the real part of ,
Could I start from:
and then continue this way:
Or is there an easier method?
Last edited by director; Feb 2nd 2013 at 02:21 PM.
The expression for sum of n terms of a GP is Now I am sure you can make out where did you go wrong
Actually it's ...
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