Existence of positive solutions for summation boundary value problem for a fourth-order difference equations

摘要

In this paper, we study the existence of positive solutions to the difference summation boundary value problem Delta(4)u(t - 2) + a(t)f (u) = 0, t is an element of {2,3,...,7}, u(0) = Delta u(0) = Delta(2)u(0) = 0, u(T + 2) = alpha Sigma(n)(s=4) u(s),