# Quadrinvariant sentence example

quadrinvariant

- For the linear forms aoxi+aix2=ax = b x there are four fundamental forms ax=a:,x i --+a i x 2 of degree-order (1, 1), x7-1--4_ ï¿½ (0, 2), a i x, 1), a b =a2+ai ï¿½ (2, 0), (iii.) and (iv.) being the linear covariant and the quadrinvariant respectively.
- Every other concomitant is a rational integral function of these four forms. The linear covariant, obviously the Jacobian of a x and x x is the line perpendicular to x and the vanishing of the quadrinvariant a x is the condition that a x passes through one of the circular points at infinity.
- For the linear forms aoxi+aix2=ax = b x there are four fundamental forms ax=a:,x i --+a i x 2 of degree-order (1, 1), x7-1--4_ Ã¯¿½ (0, 2), a i x, 1), a b =a2+ai Ã¯¿½ (2, 0), (iii.) and (iv.) being the linear covariant and the quadrinvariant respectively.