The aim of this paper is to show certain properties of the Green’s functions related to the Hill’s equation coupled with various two point boundary value conditions. We will obtain the expression of the Green’s function of Neumann, Dirichlet, Mixed and anti-periodic problems as a combination of the Green’s function related to periodic ones. As a consequence we will prove suitable results in spe...

We use the monotone iterative technique with upper and lower solutions in reversed order to obtain two monotone sequences that converge uniformly to extremal solutions of second order periodic boundary value problems and periodic solutions of functional differential equations(FDEs).

For higher order systems of differential equations solvability and correctness conditions of periodic type boundary value problems are established.

In this paper, we show that the monotone iterative technique yields two monotone sequences that converge uniformly to extremal solutions of fourth order periodic boundary value problems and periodic solutions of functional differential equations.

In this paper, we describe a systematic development of the different types of perturbations methods in the theory of differential and integral equations. A special quadratic perturbation of the periodic boundary value problems of second order ordinary differential equations is studied in detail for different aspects of the solutions. An existence theorem is proved under mixed generalized Lipsch...