Oscillation of second-order nonlinear noncanonical differential equations with deviating argument

The purpose of this paper is to study the second-order nonlinear noncanonical differential equation r ( t ) y ′ ( t ) ′ + p ( t ) f ( y ( τ ( t ) ) ) = 0 under the condition ∫ ∞ 1 r ( t ) d t ∞ . Contrary to most existing results, oscillation of the studied equation is attained via only one condition. We consider both delay and advanced differential equations. A particular example of Euler type equation is provided in order to illustrate the significance of our main results.