clear
syms s t Y

f=5*dirac(t-2);

F = laplace(f,t,s);

Y1 = s*Y - 2;
Y2 = s*Y1 - 1;

Sol = simplify(solve(Y2 + 4*Y1 +3*Y -F, Y))
% pause
sol = ilaplace(Sol,s,t)
ezplot(sol,[0 10 -2 2])
