Of course I can see that i*(i+1)=(i-1) but is there some way (long division?) to show this in general? To show for example that i = {(2+i)(3+i)/(2-i)(3-i)}. Or to come up with these equivalencies, does one just multiply i by whatever you desire in the later expansion. I am reading about Schellbach's formulae to calculate Pi from i.(adsbygoogle = window.adsbygoogle || []).push({});

Thanks, Howard

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# Why is thes true: i=(i-1)/(i+1)

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