... Corporation Boundary Value Problems Volume 2009, Article ID 103867, 34 pagesdoi:10.1155/2009/103867 Research Article An Approximation Approach to Eigenvalue Intervals for Singular Boundary Value Problems with ... singular at t 0, 1andu 0. Also our nonlinearity may change sign and be superlinear at u ∞. Our main existence results Theorems 1.1, 1.2 and 1.4 are new seeRemark 1.5, Examples 3.1 and 3.2.A ... boundary value problem −u gt, uλht, u,t∈ 0, 1,u00 u1,whereg h may be singular at u 0, t 0, 1, and may change sign and be superlinear at u ∞. The approach is based on an approximation...