Transformation to Lienard form

Abstract

We show that certain two-dimensional differential systems can be transformed to a system of Li'{e}nard type. This enables known criteria for the existence of a centre for Li'{e}nard systems to be exploited, so extending the range of techniques which are available for proving that conditions which are known to be necessary for a centre are also sufficient.

Keywords

• Ordinary differential equations
• polynomial systems
• Lienard systems.