function sol = prob_4_3
% 
% Written by:
% -- 
% John L. Weatherwax                2005-05-07
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

sol = dde23(@ddes, [0.5 1], @history, [0, 1]);
plot(sol.x,sol.y)

%==========================================

function v = history(t)
% HISTORY - 
%   
v = [ exp(t+1); 
      exp(t+0.5); 
      sin(t+1); 
      exp(t+1);
      exp(t+1);
      ];

function dydt = ddes(t,y,Z)

dydt = [ Z(5,2)+Z(3,2);
	 Z(1,2)+Z(2,1);
	 Z(3,2)+Z(1,1);
	 Z(5,2)*Z(4,2);
	 Z(1,2);
	 ];