About Sign-Constancy of Green's Function of Two-Point Problem for Impulsive Second Order Delay Equations

In our research we consider the  linear second order differential equation with delay and impulses. We build Green's functions for the two-point boundary conditions problem. Using Green's functions we find necessary and sufficient conditions of positivity of Green's functions for this impulsive equation coupled with two-point boundary conditions in the form of theorems about differential inequalities.