Center for General Education, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan
Copyright © 2009 Tsing-San Hsu and Huei-Li Lin. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
We study existence and multiplicity of positive solutions for the following Dirichlet equations: in , on , where is a bounded domain with smooth boundary , , , , , and are
continuous functions on which are somewhere positive but which may change sign on .