>> num=[4];
>> den=[1 0.5 0];
>> v=[-5 5 -5 5];
>> axis(v);

syms Y s y(t) t
 
laplace(10*diff(diff(y(t)))+0.4*diff(y(t))+4*y(t))
Y1=s*Y;
Y2=s*Y1;
sol=solve(10*Y2+0.4*Y1+4*Y-1,Y);
pretty(sol)
 
num=[1];
den=[10 0.4 4];
h=tf(num, den);
[A,B,C,D]=tf2ss(num, den)

syms x y;
u=dsolve('D2y+0.04*Dy+0.4*y=0','x')
U=dsolve('D2y+0.04*Dy+0.4*y=0','y(0)=1','Dy(0)=1','x');
subs_U=subs(U,x,0:0.1:250);
t=0:0.1:250;
plot_U=double(subs_U);
plot(t,plot_U)
hold on

figure
num=[1];
den=[10 0.4 4];
h=tf(num, den);
step(h)

>> controlSystemDesigner(tf(1,[1,2]))

>> help tf
tf - Transfer function model

    Use tf to create real-valued or complex-valued transfer function models, or to
    convert dynamic system models to transfer function form.

    sys = tf(numerator,denominator)
    sys = tf(numerator,denominator,ts)
    sys = tf(numerator,denominator,ltiSys)
    sys = tf(m)
    sys = tf(___,Name,Value)
    sys = tf(ltiSys)
    sys = tf(ltiSys,component)
    s = tf('s')
    z = tf('z',ts)