%F1
[x, y, z] = ellipsoid(0,0,0,2*sqrt(5),sqrt(10),sqrt(10),120);
surfl(x, y, z)
hold on
%F2
syms x y;
z=4-x.^2-y.^2;
ezsurf(subs(z),60)
grid on
axis([-5,5,-5,5,-5,5])
