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From: carlson@lance.tis.llnl.gov (John Carlson)
Newsgroups: comp.graphics,sci.math
Subject: Curve normal to two circles
Message-ID: <439@ncis.tis.llnl.gov>
Date: 1 Sep 89 01:40:12 GMT
Sender: news@ncis.tis.llnl.gov
Reply-To: carlson@lance.tis.llnl.gov (John Carlson)
Organization: Lawrence Livermore National Laboratory, Livermore CA
Lines: 18

I spent last night puzzling over this one, I still don't have an answer.

Given:
	A, B circles in R2 and an two points P & Q, one on
each circle (P on A, Q on B).

Construct a curve C with endpoints P & Q such that the curve is
normal to A & B at P & Q.  C only intersects A & B at P & Q.  The
function describing the curve should be differentiable at all
points on the curve except P & Q.  C is made up of at most 2
segments (3 parametric quadratics won't do! :-).


Remember, C only intersects A & B at P & Q (Otherwise the
problem is cake).

John Carlson
carlson@tis.llnl.gov