Lines meeting four tangents of a curve of order three in 3-space

Abstract

Let C be a directly differentiable curve of order 3 in real projective 3-spaceP3; cf. 3. It is known that there exist 4 tangents of C which are met by a line; cf. 3. The purpose of this paper is to show that, in fact, any 4 tangents of C are met by exactly 2 lines; cf. Theorem 3.3.