On a boundary value problem for a differential equation with variant retarded argument

摘要

In this paper, we applied two approximate methods for the solution of a boundary value problem for a differential equation with retarded argument: x′'(t) + a(t)x(t − τ(t)) = f(t), x(t) = ϕ(t) (λ0 ≤ t ≤ 0) x(T) = xT, where 0 ≤ t ≤ T and a(t), f(t), τ(t) ≥ 0 (0 ≤ t ≤ T) and ϕ(t)(λ0 ≤ t ≤ 0) are known continuous functions.