Makeup problem: $(10$ points$)$

Rearranged van der Pol equation looks like:

$x^{\text{'}}=[y-F(x)]$

$y^{\text{'}}=-\frac{1}{}x$

Where $F(x)=\frac{1}{3}{x}^3-x.$ When $>>1,$ the system is like a relaxation oscillation. Please use matlab to redo the analysis I did in class $($i$.$e$.,$ plot the nullcline, then plot the trajectory on the same plot, showing fast and slow dynamics$).$ In addition, plot a figure of $x($or y$)$ VS Time, to show there are indeed two very different time scales.

Deliverables:

Your matlab code and figures, along with some text describing your observations.