In mathematics, a directrix is a

curve In mathematics, a curve (also called a curved line in older texts) is an object similar to a line (geometry), line, but that does not have to be Linearity, straight. Intuitively, a curve may be thought of as the trace left by a moving point (ge ...

associated with a process generating a geometric object, such as: *

Directrix (conic section) In mathematics, a conic section, quadratic curve or conic is a curve obtained as the intersection of the surface of a cone with a plane. The three types of conic section are the hyperbola, the parabola, and the ellipse; the circle is a special ...

Directrix (generatrix) In geometry, a generatrix () or describent is a point, curve or surface that, when moved along a given path, generates a new shape. The path directing the motion of the generatrix motion is called a directrix or dirigent. Examples A cone can b ...

Directrix (rational normal scroll) In mathematics, a rational normal scroll is a ruled surface of degree ''n'' in projective space of dimension ''n'' + 1. Here "rational" means birational to projective space, "scroll" is an old term for ruled surface, and "normal" refers ...

Other uses

*''Directrix'' is a spaceship in the

Lensman series The ''Lensman'' series is a series of science fiction novels by American author E. E. "Doc" Smith. It was a runner-up for the 1966 Hugo award for Best All-Time Series, losing to the ''Foundation'' series by Isaac Asimov. Plot The series begi ...

of novels by E. E. Smith. *''Directrix'' is the name of a Dubai-based alternative rock band. {{mathdab