We improve, simplify, and extend on quasi-linear case some results on asymptotical stability of ordinary second-order differential equations with complex-valued coefficients obtained in our previous paper [G.R. Hovhannisyan, Asymptotic stability for second-order differential equations with complex coefficients, Electron. J. Differential Equations 2004 (85) (2004) 1-20]. To prove asymptotic stability of secondorder differential equations, we establish stability estimates using integral representations of solutions via asymptotic solutions and error estimates. Several examples are discussed.
Main resultsConsider the second-order differential equationwhere the coefficients 2f (t) and g(t, x(t), x (t)) are complex-valued continuous functions of time t.