MATLAB coded would also help me understand as it is similar to Octave

4. (20 points) A so-called van der Pol oscillating circuit is described by the differential equation dr dt Write or modify an Octave program that uses RK4 for systems to approximate the solution to this system with e 1, subject to the initial conditions r(0) da dt It=0 0.5 = Follow the solution for several oscillations, say on the interval 0 position and velocity as a function of time. st 2T, and plot the