The Oscillation and Nonoscillation Theorems for A Class of General Second Order Functional Differential Equations

The purpose of this paper is to give some sufficient conditions on f andg for ensuring that all solutions or all bounded solutions of general secondorder functional dlfferential equation 〔r(t)g(y′(t))〕′+ f(t,y(t),y(p(t)),y′(t),y′(q(t)))=0are oscillatory,or it has at least one bounded nonoscillatory solution.