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directrix

play
noun di·rec·trix \-ˈrek-triks\

Definition of directrix

plural directrixesplay \-trik-səz\ also directricesplay \-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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