OSCILLATION CRITERIA FOR FORCED SECOND-ORDER MIXED TYPE QUASILINEAR DELAY DIFFERENTIAL EQUATIONS

This article presents new oscillation criteria for the second-order delay differential equation (p(t)(x'(t))alpha)' + q(t)x alpha(t - tau) + Sigma(n)(i=1)q(i)(t)x(alpha i) (t - tau) = e(t) where tau >= 0, p(t) is an element of C(1)inverted right perpendicular0, infinity), q(t), q(i)(t), e(t) is an element of Cinverted right perpendicular0, infinity), p(t) > 0, alpha(1) > ... > alpha(m) > alpha > alpha(m+1) > ... > alpha(n) > 0 (n > m >= 1), alpha(1), ... , alpha(n) and alpha are ratio of odd positive integers. Without assuming that q(t), q(i)(t) and e(t) are nonnegative, the results in [6, 8] have been extended and a mistake in the proof of the results in [3] is corrected.