Directed line segment, direction angle, direction cosine, direction number
Cylindrical and spherical coordinates
The function f(x, y, z) and associated matrices E and e
Diameters and diametral planes
Centers of the quadric surfaces
Derivation of equations for diametral planes and centers
Changes in equation coefficients produced by translation and rotation of the coordinate system
Simplification of the general equation of the second degree by translation
Reduction of the general equation of the second degree to canonical form
Principal planes and eigenvectors
Quadratic forms, canonical forms of quadric surfaces with centers
Equations relating the canonical system coordinates to the expressions for the coordinate planes