On the existence of eventually positive solutions of fourth-order quasilinear differential equations

摘要

The fourth-order quasilinear differential equation(u"(alpha-1)u")" + q(t)u(beta-1)u = 0 (1.1)is considered under the assumptions that alpha > 0, beta > 0 and q(t) is a positive continuous function on an interval [a, infinity), a > 0, and the necessary and sufficient integral conditions for the existence of eventually positive solutions of (1.1) are established. (C) 2004 Elsevier Ltd. All rights reserved.