Powerseries of a natural logarithm

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center o bass
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Homework Statement


Show that

[tex]\frac{1}{x} \ln \frac{x+1}{x-1} = \sum_0^\infty \frac{2x^{2n}}{2n+1}[/tex].


2. The attempt at a solution
I tried to use the relation

[tex]\frac{1}{1+x} = \frac{d}{dx}\ln (1+x)[/tex]

and expand as a geometric series, but this did not lead anywhere since I then ended up with an alternating series.

Anyone got any ideas of where to start?
 
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Yes, so I could subtract the two resulting series... and I see now that it will actually lead trough. Ofcourse I knew about the property, but I did not see how it would get rid of the 'alternation'. However I do see that now because of the cancellation of terms.

Thank you!