Congruences of the Elliptic Type
Congruences of the Elliptic Type
Introduction.Let i be a line of a rectilinear congruence; X, Y, Z, its direction-cosines; and x,y,z, the coordinates of the point in which L cuts a surface of reference S.These six quantities are functions of two parameters, say u and v, which we assume to be real.As usual we putOf …