We consider the boundary value problemwhere Ω ⊂ R N is a bounded domain, φ is a nonnegative function in L ∞ (Ω) such that φ > 0 on some subset of Ω of positive measure, and g : [0, ∞) → R is continuous. We establish the existence of three positive solutions when g(0) > 0 (positone), the graph of s α+1 g(s) is roughly S-shaped, and α > 0. We also prove that there exists at least one positive solution when g(0) < 0 (semipositone), g(s) is eventually positive for s > 0, and 0 < α < 1.We employ the method of sub-super solutions to prove our results.