We consider positive solutions of the Dirichlet problem u(x) + λf(u(x)) = 0 on (−1, 1), u(−1 ) =u(1) = 0. depending on a positive parameter λ. Each solution u(x) is an even function, and hence it is uniquely identified by α = u(0). We present a formul . . .

We present exact multiplicity results for the boundary value problems of the type (1.1) u’’+ λf(x, u) = 0 for − L < x < L, u(−L) = u(L) = 0, with the nonlinearity f behaving like a cubic polynomial in u.

We revisit the question of exact multiplicity of positive solutions for a class of Dirichlet problems for cubic-like nonlinearities, which we studied in 161. Instead of computing the direction of bifurcation as we did in [6], we use an indirect approa . . .