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Topic: Harmonic set of points internal/external division NEED HELP
Replies: 4   Last Post: Nov 7, 2012 8:07 AM

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Richard Chandler

Posts: 1
From: Normal, IL
Registered: 9/18/11
Re: Harmonic set of points internal/external division NEED HELP
Posted: Sep 18, 2011 2:12 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

You're right, it's not plain English. I remember scratching my head on this one.

I'm enclosing a GSP sketch that will illustrate it. If you don't have GSP, write me back.

If AC means the distance between points A and C, BD means the distance between B and D and so on, and if a distance in the direction of the ray AB is positive and a distance in the direction of the ray BA is negative, then a harmonic set is one where

AC AD
-- = - --
CB DB

See also http://mathworld.wolfram.com/HarmonicRange.html



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