Response of a circuit without using SIMULINK ?

I'd like to plot the frequency response of this circuit, I know how to do this on Electronic Workbench or Multisim but how is it possible to do it in Matlab without using Simulink ?

What i've done is a simple solution that give answer but it is impossible to plot it response,

syms r1 r2 l1 v i

v=12;
r1=6;
r2=12;
l1=2;
i=v/r2;

s1 = r1+r2;
T=l1/s1;

Answer 1

[Azzi Abdelmalek]

You have some work to do

1. find a relation between your current i1(t) which is the output of your system and the voltage u(t) wich is the input of your system
2. because you are using a switch meas that u(t) is a step signal u(t)=12 step(t)
3. It's easier to do it with Laplace transform U(p)=12/p then find H(p)=I1(p)/U(p) which is your transfer function
4. when 1 2 and 3 are done look this example

%H(p)=10/(2p+3)

N=10;D=[2 3]
model=tf(N,D)
Bode(model)

% is your frequency response with logarithm scale. this requiert a control system toolbox. you can also use freqresp