I should be writing math textbooks.
What does anyone use this particular equality for?
On 10/30/05, Mathieu Bouchard <matju@artengine.ca> wrote:
On Sat, 29 Oct 2005, Chuckk Hubbard wrote:
> Just a note, I came up with a pretty obvious proof for:
> SUM (k=0 to N-1) i^k = (i^N - 1) / (i - 1)
> (i - 1) (i^0 + i^1 + i^2 + .... + i^(N-1))
> =
> -i^0 + i^1 - i^1 + i^2 - i^2 ... + i^(N-1) - i^(N-1) + i^N
> = i^N - 1
> All the terms cancel except the lowest and highest powers of i.
That's the same proof that is used in all math textbooks.
____________________________________________________________________
Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju
Freelance Digital Arts Engineer, Montréal QC Canada
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