“…In addition to the familiar approach of obtaining the stability of the synchronized state, we also show that the method could be used to estimate the onset of synchronization. Basically, a given system is stable, if there exist a continuous, positive definite, differentiable, and radially unbounded function (the Lyapunov function, V ) defined along the system's trajectory, such that its time derivativeV ≤ 0, as t → ∞ [27,28,30]. To begin with, we shall apply the following lemma to prove the main theorem of this paper.…”