function simpleFb()
[T,Y] = ode15s(@model,[0:(7/6):7],[1 0.6 0]);
plot(T,Y(:,1),'x-',T,Y(:,2),'o-',T,Y(:,3),'+-');
legend('Y_1','Y_2','Y_3');


function dy = model(t,y)
k=[0.9, 0.9, 1.0, 1.0, 0.6,0.6 0.8];
dy = zeros(3,1);   
dy(1) = k(1)* (k(2)/(y(3)+k(2))) - k(3)* y(1);
dy(2)= k(4)* y(1) - k(5)* y(2);
dy(3) = k(6)* y(2) - k(7)* y(3);
