function graphF(F)
%plots a contour plot of our function
t=linspace(0,2*pi);
s=linspace(0,2*pi);
V=zeros(100);%space for the function values
for i=1:100
    for j=1:100
        V(i,j)=feval(F,[t(i);s(j)]);
    end
end
contour(t,s,V',50)