%Sestrojte graf funkce y=x^2+y^2
figure
xx=-5:0.01:5;
yy=-5:0.01:5;
[x y]=meshgrid(xx,yy);
z=x.^2+y.^2;
mesh(x,y,z)

%Sestrojte graf funkce y=(x^2+y^2)*sin(1./(x^2+y^2))
figure
xx=-5:0.01:5;
yy=-5:0.01:5;
[x y]=meshgrid(xx,yy);
z=(x.^2+y.^2).*sin(1./(x.^2+y.^2));
mesh(x,y,z)

%Sestrojte graf funkce y=sqrt(|x*y|)
figure
xx=-5:0.01:5;
yy=-5:0.01:5;
[x y]=meshgrid(xx,yy);
z=sqrt(abs(x.*y));
mesh(x,y,z)