quadric

/kwod-rik/US // ˈkwɒd rɪk //UK // (ˈkwɒdrɪk) maths //

四分法,四分体,四元组,四分法的

Definitions

adj.形容词 adjective

n.名词 noun

1
- : a quadric function.
- : a surface such as an ellipsoid or paraboloid as defined by a second-degree equation in three real variables.

Now from a quadric equation we derive, in like manner, the notion of a complex or imaginary number such as is spoken of above.
Consider first a numerical quadric equation with imaginary coefficients.
Evidently the method gives for L a quadric equation, which is the “resolvent” equation in this particular case.
If a line moves so that it always cuts three given lines of which no two meet, then it generates a ruled quadric surface.
Each ray cuts its corresponding plane in a point, the locus of these points is a quadric surface.