Finding Alternative Representations for the Convergent Series Ʃ ((-1)^(i-1))/i

venom192
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Homework Statement



I basically need to know if the series Ʃ ((-1)^(i-1))/i can be represented in other ways (e.g. a Taylor series, but I doubt it). I know it converges to ln2, but I need to know if there's a series like x^2, x^4, ... or something like it that I can represent the series with.

Homework Equations



Ʃ ((-1)^(i-1))/i for i=1 to q, where q is a finite, but very large number

The Attempt at a Solution



My calc textbook doesn't examine that series for anything besides its convergent nature, and I can't find any online resources for it. Any help would be appreciated.
 
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I'm not sure if I understand what you are asking... But have you tried expanding ln(1+x) as a Taylor series?
 
clamtrox said:
I'm not sure if I understand what you are asking... But have you tried expanding ln(1+x) as a Taylor series?

Thanks for the reply. This question specifically pertains to the series I asked about - I was just using the Taylor series as a possibility of an alternate representation of the series. After looking at my old calc textbook, I see that I was way off base suggesting a Taylor series.

I'll rephrase this - Is it possible to rewrite the series Ʃ(-1^i)/i as another type of series that contains a quadratic term?
 
Quadratic in what? You can of course develop the series at different points. If you solve for the series of ln (3/2+x) then you'll end up with series containing powers of 1/2.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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