a. Plot the response \(x\) by using the step and initial commands, showing the step response, the initial response and the total response in one figure. Verify the steady-state value of \(x\).
b. Plot the response \(x\) by using the lsim command.

\(u(t)\) denotes the unit step.
\(6 \ddot{x}+11 \dot{x}+3 x=u(t), x(0)=1, \dot{x}(0)=-\frac{1}{2}\)