Two questions

*To*: mathgroup at yoda.physics.unc.edu*Subject*: Two questions*From*: KUMM at pierre.mit.edu*Date*: Thu, 6 Aug 1992 18:21:00 -0400 (EDT)

I have two Mathematica questions for the assembled multitudes. (1) I would like to take two quadric surfaces, e.g. two paraboloids 8-(x^2)-(y^2),(x^2)+3(y^2), graph the two together AND Then graph the intersection on the xy plane "below" the two surfaces. In general, how do we get the surfaces to "cast a shadow". (2) Even if I calculate the intersection of the above myself, (x^2)+2(y^2)=4, how can I get Mma to graph this. In general, how do we graph functions expressed implicitly? Thanks, E.A.Kumm (kumm at mitlns.mit.edu)