- Geometry. a fixed line used in the description of a curve or surface.
- Archaic. a directress.
Origin of directrix
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for directrix
As necessary as the directrix is to the curve, so are the corresponding laws to the State.
Directrix, a fixed line that is required for the description of a curve.The New Gresham Encyclopedia
Similarly, in an hyperbola a vertex is nearer 704 to the directrix than to the focus.
If a parabola roll on another parabola, their vertices coinciding, the focus of the first traces out the directrix of the second.
With your permission I will add a few words to those I have already uttered with regard to the directrix.
- geometry a fixed reference line, situated on the convex side of a conic section, that is used when defining or calculating its eccentricity
- a directress
C17: New Latin, feminine of director
- A straight line used in generating a curve such as a parabola.
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