Sufficient conditions for the oscillation of the neutral equation d/dt[x(t) - R(t)x(t - r)] + P(t)x(t - r) - Q(t)x(t - δ) = 0,where P,Q,R ∈ C([t0,∞), R+), and r, T, δ ∈ (0,∞), are obtained for the case where former results can not be applied.
In this paper, the boundedness and the stability of solutions for a class of fourth order nonlinear differential equations are studied by using the method of Liapunov function. The sufficient conditions which guarantee the boundedness and stability of solutions are preasented.
