7.3.4 Consider the system x=x(1-4x-2)-y(1+x), y=y(1-4x-2)+2x(1+x). a) Show that the origin is an unstable fixed point. b) By considering v, where V = (1-4x² - y²)², show that all trajectories approach the ellipse 4x² + y² = 1 as t→ ∞o.