right strophoid
- Autor:
- vera viana
a strophoid is the locus of points P and P', equidistant from the intersection of two straight lines (ON and AN, in the image below).
A is the strophoid pole, NA its directrix, and OA, the vector.
if OA and NA are perpendicular, the resulting locus is a right strophoid.
A, P and P' belong to the circle centred in N.
A Book of Curves - E. H. Lockwood, 1961
Structure - Luc Joly, 1971
http://www.mathcurve.com/courbes2d/strophoiddroite/strophoiddroite.shtml
http://geometrias.blogspot.pt/2009/08/estrof.html