How to find the limit of a transfer function defined using tf?

I defined a transfer function using:

>> sys1=tf([20 20],poly([-4 -3]))

sys1 =

20 s + 20

--------------

s^2 + 7 s + 12

now i want to find its limit s->0, how do i do this?

tried using limit(sys1) but it didnt accept it

Answer 1

[Serhii Tetora]

sys1=tf([20 20],poly([-4 -3]));
[Num,Den] = tfdata(sys1,'v');
syms s
sys_syms=poly2sym(Num,s)/poly2sym(Den,s);
lim = limit(sys_syms,s,0)

[Janno Rhey Don]

thank you it worked perfectly!