We investigate the existence of three positive solutions of fourth order problems with clamped beam boundary conditions
where is a parameter, is nondecreasing, , for all . Especially, we obtain an S-shaped unbounded connected component in the symmetric positive solutions set. The proof is based on the directions of a bifurcation.
"Three positive solutions of fourth-order problems with clamped beam boundary conditions." Rocky Mountain J. Math. 50 (6) 2235 - 2244, December 2020. https://doi.org/10.1216/rmj.2020.50.2235