OSCILLATION OF NONLINEAR NEUTRAL DELAY DIFFERENTIAL EQUATION WITH SEVERAL COEFFICIENTS

In this article, we show that the oscillation of all solutions to the neutral equation [x (t) − R (t) N (x (t − κ))]′ + Xn i=1 Pi (t) Fi (x (t − τi)) − Xm j=1 Qj (t) Gj (x (t − σj )) = 0 is implied by the oscillation of all solutions to the linear equation [x (t) − rx (t − κ)]′ + Xn i=1 pix (t − τi) − Xm j=1 qjx (t − σj ) = 0. In these equations, R,Pi , Qj are positive and continuous functions, and κ, τi , σj are positive constants that represent delays