“…There are many fourth order differential equations like problem (1.1) in material mechanics, in modelling bending equilibria of elastic beams, etc. Various interesting results on fourth-order boundary value problems have been obtained, for instance, in [1,2,9,11,13,14,[18][19][20][21][22]. Ma [14], using variational methods, has obtained the existence of at least two positive solutions for the problem…”