t=[0:0.1:20];
f=1-2*exp(-.24*t).*(cos(2*t));
plot(t,f);
hold on
plot(t,(1+2*exp(-0.24*t)),'--')
plot(t,(1+2*exp(-0.24*t)),'--')
xlabel('The t axis ');
ylabel('The f axis ');
title('The plot of f versus t ');
grid on;
hold off
