Oscillations of delay differential equations with variable coefficients

Abstract

The purpose of this paper is to obtain a sharp sufficient condition for the oscillation of the delay differential equation
$$y^{\prime}(x)+q(x) y(x-\tau)=0, \quad x \geq x_0,$$
where $q(x) \in C\left(\left[x_0, \infty\right), R^{+}\right)$ which improves previously known results.