Let phi:R-->R be defined by phi(s)=\s\(p-2)s, with p > 1 a fixed number. We extend Sturm Comparison Theorem of the linear differential equation d/dt[r(t)u'(t)] + c(t)u(t) = 0 to the nonlinear differential equation (E) d/dt{r(t)phi(u'(t))} + c(t)phi(u(t)) = 0, by using the Wirtinger inequality. A Lyapunov inequality and some oscillation criteria of(E) are also given.
關聯:
PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH SECTION A-MATHEMATICS