Mohamed Grazem

On the Coexistence of Two Limit Cycles Enclosing a Node in a Class of Planar Differential Systems of Degree Six

ABSTRACT In this paper, we look at a special type of six‐degree polynomial differential systems in the plane. We establish the coexistence of two limit cycles in these systems, both surrounding a single node. It is well known that, for systems of even degree, proving the coexiste...