Consider the system
{
dot{x} = x,
dot{y} = y - y^2.
Sketch the phase portrait by completing the following steps. First, find and classify the fixed points. Then sketch the nullclines (that is, a set of points in the phase space where dot{x} = 0 and the set of points where dot{y} = 0). Finally, fill in representative trajectories using the classification of the fixed points.