Bácsó, SándorSzilasi, Zoltán2024-09-042024-09-042006-06-01Teaching Mathematics and Computer Science, Vol. 4 No. 1 (2006) , 167-1771589-7389https://hdl.handle.net/2437/379576The paper deals with hyper-quadrics in the real projective 4-space. According to [1] there exist 11 types of hypersurfaces of 2nd order, which can be represented by 'projective normal forms' with respect to a polar simplex as coordinate frame. By interpreting this frame as a Cartesian frame in the (projectively extended) Euclidean 4-space one will receive sort of Euclidean standard types of hyper-quadrics resp., hypersurfaces of 2nd order: the sphere as representative of hyper-ellipsoids, equilateral hyper-hyperboloids, and hyper-cones of revolution. It seems to be worthwhile to visualize the "typical" projective hyper-quadrics by means of descriptive geometry in the (projectively extended) Euclidean 4-space using Maurin's method [4] or the classical (skew) axonometric mapping of that 4-space into an image plane.application/pdfprojective quadricsEuclidean and projective spacesMaurin’s projectionaxonometryfolyóiratcikkOpen AccessSándor Bácsó and Zoltán Szilasihttps://doi.org/10.5485/TMCS.2006.0114Teaching Mathematics and Computer Science14Teach. Math. Comp. Sci.2676-8364