A methodology for experimentation in Cabri 2 Plus and Cabri 3D using parabolas as examples

Abstract

I will show how: 1/ Cabri 2 Plus allows us to rediscover theorems related to the cross ratio of four tangents to a parabola. 2/ Cabri 3D allows us to see that the parabola y = x² is the intersection of a cone and a plane. I will analyze these explorations using a framework that I have recently developed, based on the work of Parzysz,Duval, Johsua and Millar.