The authors study the singular superlinear problem
The function is allowed to be singular at both and . In addition, is not assumed to be nonnegative. The assumption of nonnegativity of has been very often required in the existing literature. Omitting this condition requires a different approach. Using topological degree theory, the authors establish conditions guaranteeing the existence of nontrivial solutions and positive solutions to the above boundary value problem. A nonsingular case is discussed as well.