摘要：In this paper, sufficient conditions for the existence of positive periodic solutions of the second-order difference equation Δ 2 u ( t − 1 ) = g ( t ) u μ ( t ) − h ( t ) u λ ( t ) + f ( t ) , t ∈ Z , are established, where g , h : Z → [ 0 , ∞ ) and f : Z → R are T-periodic functions, λ , μ > 0 . MSC:34B15.
