Directrix

In mathematics, a directrix is a curve associated with a process generating a geometric object, such as: Directrix (conic section) Directrix (ellipse) Directrix (generatrix) Directrix (rational normal scroll)

==Other uses== Directrix is a spaceship in the Lensman series of novels by E. E. Smith. Directrix is the name of an indie alternative band in Chicago. Directrix - a feminine form of director in the context of grammatical gender.