Plot phase portraits for the Lienard system [begin{aligned} & x^{prime}=y-muleft(x^{3}-x ight) & y^{prime}=-x end{aligned}] for a

Plot phase portraits for the Lienard system

\[\begin{aligned} & x^{\prime}=y-\mu\left(x^{3}-x\right) \\ & y^{\prime}=-x \end{aligned}\]

for a small and a not so small value of \(\mu\). Describe what happens as one varies \(\mu\).