Now we want to look at the phase portraits of systems with complex Eigenvalues. The equilibrium of a system with complex Eigenvalues that have no real part is a stable center around which the trajectories revolve, without ever getting closer to or further from equilibrium. The equilibrium of a system with complex Eigenvalues with a positive real part is an unstable spiral that repels all trajectories. The equilibrium of a system with complex Eigenvalues with a negative real part is an asymptotically stable spiral that attracts all trajectories.
Read MoreGiven the equation of a circle, we can put the equation in standard form, find the center and radius of the circle from the standard form, and then use the center and radius to graph the circle. Alternately, given the graph of the circle, we can identify the center and radius from the graph and then plug those values into the standard equation of the circle in order to get its equation.
Read MoreTo find the radius, it’s important that we take the square root of the right-hand side, and not just the full value from the right
Read More