0 a curve or surface that is described by an equation (= a mathematical statement in which you show that two amounts are equal) that has at least one variable (= a number that can change) that is squared (= multiplied by itself)
1 described by an equation (= a mathematical statement in which you show that two amounts are equal) that has at least one variable (= a number that can change) that is squared (= multiplied by itself):
a quadric surface
Another class of integrable billiard tables appears on quadrics.
Superquadrics are formed by incorporating additional parameters into the quadric equations to provide increased flexibility for adjusting object shapes.
A frequently used class of objects are the quadric surfaces, which are described with second-degree equations (quadratics).
The quadric is unbounded and the total measure of is infinite.
The image is a quadric, and is easily seen to contain two one-parameter families of lines.
Over the complex numbers this is a quite general non-singular quadric.
The stereographic projection presents the quadric hypersurface as a rational hypersurface.
A quadric is thus an example of an algebraic variety.