Definition of directrix
1 archaic : directress
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
Learn More about directrix
Britannica.com: Encyclopedia article about "directrix"
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