PERIODIC SOLUTIONS OF NEARLY LYAPUNOV SYSTEM IN THE EXTERNAL RESONANCE CASE

The paper deals with the problem of bifurcation of 2ya-periodic Asolutions of a nearly Lyapunov system in the case of external Aresonance. It gives the method which allows one to construct both the Abifurcation curve and the corresponding 2ya-periodic solutions in the Aform of convergent series in fractional powers of a small parameter. As an example, the bifurcation problem of 271-periodic pendulum Amotions emerging from its conic motion is considered.