What is an equilibrium point? * A point at which the system's state dynamics are zero A point at which the system becomes internally stable A point at which we calculate the linear approximation A point at which the system becomes unstable What is the implication of the internal stability in the sense of Lyapunov? If the initial condition is close enough to the equilibrium point, the whole trajectory stays close enough to it If the trajectory of the system stays close enough to the equilibrium point, the initial condition shall also remain close enough to it If the initial condition is far enough from the equilibrium point, the whole trajectory stays close enough to it If the initial condition is close enough to the equilibrium point, the whole trajectory stays far enough enough from it