Quasi normal sectors and orbits in regular critical directions of planar system

Abstract

This paper deals with the qualitative behavior of orbits at degenerate singular point with the method of quasi normal sector, which is a generalization of Frommer’s normal sectors. Several examples show that this method is more effective than the well-known methods of Z-sectors, normal sectors and generalized normal sector.

Keywords

Normal sector / Generalized normal sector / Quasi normal sector

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