We consider multipoint and two-point BVPs for second order ordinary differential equations with a Carathéodory right hand side. We prove the existence of solutions provided there exist upper and lower solutions of the BVP and the upper solution is less than the lower one.
We prove the existence of solutions of four-point boundary value problems under the assumption that fulfils various combinations of sign conditions and no growth restrictions are imposed on . In contrast to earlier works all our results are proved for the Carathéodory case.
This paper is concerned with existence and uniqueness of solutions of the three-point problem . The problem is at resonance, in the sense that the associated linear problem has non-trivial solutions. We use the method of lower and upper solutions.
Page 1 Next