Asymptotic behavior of solutions and positive solutions of differential delayed equations.

*(English)*Zbl 1129.34050By employing an implicit integral inequality, the authors establish an existence criterion for positive solutions of the following linear delayed differential equation

$${y}^{\text{'}}\left(t\right)=-\sum _{i=1}^{m}{c}_{i}\left(t\right)y(t-{r}_{i}\left(t\right))-d\left(t\right)\xb7$$

Structure formulas for solutions of this equation and its corresponding homogeneous equation are also discussed.

Reviewer: Qiru Wang (Guangzhou)