A plane section, presumably; so change coordinates making the plane z = 0 , and the remaining equation is quadratic in x,y . WFL On 5/20/19, Bill Gosper <billgosper@gmail.com> wrote:

Is a section of an elliptical cone a Conic Section? —rwg _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun