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directrix

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noun di·rec·trix \-ˈrek-triks\

Definition of directrix

plural di·rec·trix·esplay \-trik-səz\ also di·rec·tri·cesplay \-trə-ˌsēz\

  1. 1 archaic :  directress

  2. 2 :  a fixed curve with which a generatrix maintains a given relationship in generating a geometric figure; specifically :  a straight line the distance to which from any point of a conic section is in fixed ratio to the distance from the same point to a focus



Origin of directrix

Medieval Latin, feminine of Late Latin director, from Latin dirigere


First Known Use: 1622


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