Michel Bataille, On the foci of circumparabolas,
Forum Geometricorum, 11 (2011) 57--63.


Abstract.   We establish some results about the foci of the infinitely many parabolas passing through three given points A, B, C. A very simple construction directly leads to their barycentric coordinates which provide, besides their locus, a nice and unexpected link with the foci of the parabolas tangent to the sidelines of triangle ABC.

[ps file] [pdf]