Abstract
We consider forced second order differential equation with p-Laplacian and damping in the form of
(r(t)phi(alpha 0) (x'))' + p(t)phi(alpha 0) (x') + (N)Sigma(j=0)q(j)(t)phi(alpha j) (x) = e(t),
where phi(alpha) (u) := vertical bar u vertical bar(alpha) sgn u, alpha(j) > 0, j = 0, 1, 2,..., N, and r, p, q(j), e is an element of C ([0, infinity), R) with r(t) > 0 on [0, infinity). Interval oscillation criteria of the El-Sayed type and the Kong type are obtained. These criteria are further extended to equations with deviating arguments. Our work generalizes, unifies, and improves many existing results in the literature.