EJERCICIO 12

function ecdif
[t,yy]=ode45(@HalfSine, [0 35], [1 0], [], 0.15);
plot(t,yy(:,1))
function y=HalfSine(t,y,z)
h=sin(pi*t/5).*(t<=5);
y=[y(2);-2*z*y(2)-y(1)+h];