Isoptics to a parabola

An isoptic of a parabola id a branch of a hyperbola. The two branches of the hyperbola correspond to supplementary angles, and appear together from the computations. Therefore the hyperbola is also called a bisoptic of the parabola. Two bisoptics of the same parabola are presented here. Move the points A and B along their respective branches. This is part of joint work with Nurit Zehavi and Giora Mann.