Lexic.us

Definition of Directrix

1. n. A directress.

Definition of Directrix

1. Noun. A female who directs; a directress. ¹

2. Noun. (geometry) A line used to define a curve or surface; especially a line, the distance from which a point on a conic has a constant ratio to that from the focus ¹

¹ Source: wiktionary.com

Definition of Directrix

1. [n -TRIXES or -TRICES]

Medical Definition of Directrix

1. 1. A directress. 2. A line along which a point in another line moves, or which in any way governs the motion of the point and determines the position of the curve generated by it; the line along which the generatrix moves in generating a surface. A straight line so situated with respect to a conic section that the distance of any point of the curve from it has a constant ratio to the distance of the same point from the focus. Source: Websters Dictionary (01 Mar 1998)

Lexicographical Neighbors of Directrix

Literary usage of Directrix

Below you will find example usage of this term as found in modern and/or classical literature:

1. A Treatise on Conic Sections: Containing an Account of Some of the Most by George Salmon (1904)
"The polar of cither focus is called the directrix of the conic section. The directrix must, therefore (Art. 169), be a line perpendicular to the axis t ..."

2. A History of Greek Mathematics by Thomas Little Heath (1921)
""But one (to us) ordinary property, the focus-directrix property, was, as it seems to me, in all probability included. • Focus-directrix property known to ..."

3. The Encyclopaedia Britannica: A Dictionary of Arts, Sciences, and General by Thomas Spencer Baynes (1888)
"2) be the focus, and XK the directrix. Draw SX perpendicular to KX, and bisect SX in A ... Let QN oe any straight line parallel to the directrix, cutting XZ ..."

4. A Treatise on the Analytic Geometry of Three Dimensions by George Salmon (1882)
"ratio to the product of the perpendiculars let fall from the point on the quadric, on two planes drawn through the corresponding directrix, parallel to the ..."

5. A Treatise on Electricity and Magnetism by James Clerk Maxwell (1892)
"It is evident from the equation, that the force whose components are —j- ds, -j— ds, and -j~ ds is perpendicular both to ds and to this directrix, ..."

6. The Theory and Practice of Absolute Measurements in Electricity and Magnetism by Andrew Gray (1893)
"The resultant of A, B, C, Ampere called the directrix. By comparison with (9) above we see that it is the magnetic induction at ds' produced by the circuit. ..."

7. Annual Report of the United States Geological and Geographical Survey of the by Geological and Geographical Survey of the Territories (U.S.), United States General Land Office, United States Dept. of the Interior (1874)
"Alliance, (track) Cleveland directrix Cleveland directrix, by profile of C. ... Crestline, (track,) by profile of PFW & CR R Crestline Cleveland directrix, ..."

8. Hermathena by Trinity College (Dublin, Ireland) (1874)
"The fixed point is, of course, the focus, and the fixed right line the directrix of the conic. From the above definition the fundamental properties of the ..."

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