with(plots):f := (x,y) -> 5*exp(-x^2-y^2)+3*exp(-(x-5)^2-y^2);plot3d(f(x,y),x=-3..7,y=-2..2,axes=normal,scaling=constrained);cpf := contourplot(f(x,y),x=-3..6,y=-2..2):fpf := fieldplot([diff(f(x,y),x),diff(f(x,y),y)],x=-3..6,y=-2..2):display({cpf,fpf});g := (x,y) -> 5*exp(-x^2-y^2)-5*exp(-(x-5)^2-y^2);plot3d(g(x,y),x=-3..7,y=-2..2,axes=normal,scaling=constrained);cpg := contourplot(g(x,y),x=-3..6,y=-2..2):fpg := fieldplot([diff(g(x,y),x),diff(g(x,y),y)],x=-3..6,y=-2..2):display({cpg,fpg});