Communications Faculty of Sciences University of Ankara Series A1: Mathematics and Statistics, cilt.70, sa.2, ss.612-621, 2021 (ESCI)
In this paper, we consider a second order nonlinear differential equation and establish two new theorems about the existence of the bounded solutions of a second order nonlinear differential equation. In these theorems, we use different Lyapunov functions with different conditions but we get the same result. In addition, two examples are given to support our results with some figures.