Amster, PabloTisdell, Christopher2021-08-182021-08-182007-11-09Amster, P., & Tisdell, C. (2007). Two classical periodic problems on time scales. <i>Electronic Journal of Differential Equations, 2007</i>(149), pp. 1-12.1072-6691https://hdl.handle.net/10877/14363We consider the generalization of two classical periodic problems to the context of time scales. On the one hand, we generalize a celebrated result by Castro for the forced pendulum equation. On the other hand, we extend a well-known result by Nirenberg to a resonant system of equations on time scales. Furthermore, the results are new even for classical difference equations.Text12 pages1 file (.pdf)enAttribution 4.0 InternationalTime scaleBoundary value problemForced pendulum equationLandesman-Lazer conditionsExistence of solutionsArticle