Uniqueness of Limit Cycles in a Liénard-Type System

In this paper, conditions that guarantee the uniqueness of limit cycles in the Liénard-type system, dx/dt=h(y)−F(x), dy/dt=−g(x), have been discussed. The conditions obtained here are different from those of Zhang and others. Several examples such as ẍ+ψ(ẋ)+q(x)φ(ẋ)=0 are given to illustrate that our results may easily be employed in practical applications.