مشخصات پژوهش

In this paper autonomous Lienard system x_ = ϕ(z - F(x)); z_ = -g(x); (1) is considered. Some suffcient and necessary conditions are presented for the system to have a positive and a negative semiorbit which starts at a point on the curve z = F(x) and approaches the origin without intersecting the x-axes which are very important in the theory of oscillation and global asymptotic stability of the solutions of this system.