Girg, Petr2019-03-192019-03-191998-11-20Girg, P. (1998). Existence of periodic solutions for a semilinear ordinary differential equation. <i>Electronic Journal of Differential Equations, 1998</i>(31), pp. 1-10.1072-6691https://hdl.handle.net/10877/7930Dancer [3] found a necessary and sufficient condition for the existence of periodic solutions to the equation ẍ + g1 (ẋ) + g0(x) = ƒ(t). His condition is based on a functional that depends on the solution to the above equation with g0 = 0. However, that solution is not always explicitly known which makes the condition unverifiable in practical situations. As an alternative, we find computable bounds for the functional that provide a sufficient condition and a necessary condition for the existence of solutions.Text10 pages1 file (.pdf)enAttribution 4.0 InternationalOrdinary differential equationPeriodic solutionsArticle