ABSTRACT
The projective viewpoint is the most general. This is of particular signif icance for quadrics. Most of their interesting and useful affine properties stem from only a few projective properties and from concepts such as po larity.
The projective viewpoint is the most general. This is of particular signif icance for quadrics. Most of their interesting and useful affine properties stem from only a few projective properties and from concepts such as po larity.