On third order coupled systems with full nonlinearities

Infeliz Carvalho Coxe, Feliz Minhós


This work sutdies the solvability of nonlinear third order coupled sistems composed by third order differential equations with L`-Carathéodory nonlinearities and two-point boundary conditions.

An adequate truncature together with Nagumo- type conditions allow the dependence of the nonlinearities on the secand derivatives. By lower and upper sulutions method is obteined strips where the unknown functions and their derivatives must lie, which provides some qualitative data on the solutions.


Coupled systems; Green functions; Nagumo-type condition; coupled lower and upper solutions


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