A

David

Darling

Dürer's shell curve

Durer's shell curve

Dürer's shell curve may be defined as follows: given a parabola and a line that is tangent to the parabola, it is the glissette of a point on a line sliding between the parabola and the tangent. It has the equation

 

(x2 + xy + ax - b2) = (b2 - x2)(x - y + a)2.