Electronic Journal of Differential Equations,
Vol. 2008(2008), No. 113, pp. 1-15.

Title: Oscillation and asymptotic behaviour of a higher order 
       neutral differential equation with positive and 
       negative coefficients
  
Authors: Basak Karpuz    (Afyon Kocatepe Univ., Turkey)
         Laxmi Narayan Padhy (K.I.S.T., Bhubaneswar, India)
	 Radhanath Rath  (Khallikote Autonomous College, India)
 
Abstract: 
 In this paper, we obtain necessary and sufficient conditions so
 that every solution of
 $$
 \big(y(t)-  p(t) y(r(t))\big)^{(n)}+
 q(t)G( y(g(t)))-u(t)H(y(h(t))) = f(t)
 $$
 oscillates or tends to zero as $t \to \infty$, where $n$ is
 an integer $n \geq 2$, $q>0$, $u\geq 0$.
 Both bounded and unbounded solutions are considered in this paper.
 The results hold also when $u\equiv 0$, $f(t)\equiv 0$, and 
 $G(u)\equiv u$.
 This paper extends and generalizes some recent results.

Submitted April 4, 2008. Published August 20, 2008.
Math Subject Classifications: 34C10, 34C15, 34K40.
Key Words: Oscillatory solution; neutral differential equation;
           asymptotic behaviour.