Positivity of the Green function for a four point fourth order focal boundary value problem. (English) Zbl 1314.34057
Summary: We consider a four point fourth-order boundary value problem of focal type. A necessary and sufficient condition for the positivity of the Green function for the problem is established.
MSC:
| 34B27 | Green’s functions for ordinary differential equations |
| 34B15 | Nonlinear boundary value problems for ordinary differential equations |
| 34B18 | Positive solutions to nonlinear boundary value problems for ordinary differential equations |
