PERIODIC SOLUTIONS OF VOLTERRA INTEGRO-DIFFERENTIAL EQUATIONS WITH RETARDED ARGUMENT AND SYMMETRIC MATRICES

In this paper, we investigate the existence, approximation and stability solutions of the periodic solutions for some Volterra integro-differential equations with retarded argument and symmetric matrices, by using numerical-analytic method for studying the periodic solutions of ordinary differential equation which were introduced by Samoilenko. These investigations lead us to improving and extending the above method. Theorem on the periodic solution are established and some necessary sufficient conditions on a compact space.