1. The problem statement, all variables and given/known data I'm learning Sturm-Liouville theory and currently studying Green's function. In the following image, the author states that [tex]y_n(x)[/tex] satisfy the "same" boundary conditions as [tex]y(x)[/tex]. 2. Relevant equations http://img2.pict.com/e9/87/37/3735148/0/1277836655.jpg [Broken] 3. The attempt at a solution How can I prove this? This is strictly for pedagogical purposes. The closest I can get to solving this problem is considering the boundary conditions for Regular Sturm-Liouville problems, which is: http://img2.pict.com/d8/f9/a0/3735157/0/1277836732.jpg [Broken] Any help appreciated!