Abstract :
Under certain conditions, it was proved that y‴(t) + a(t)y″(t) + b(t)y′(t) + c(t)y(t) = f(t) oscillates (i.e., admits an oscillatory solution) if [formula] Further, it was observed that (*) is a necessary and sufficient condition for oscillation when a(t), b(t), c(t), and f(t) are real constants.
