TY - JOUR JF - jsci JO - VL - 12 IS - 1 PY - 2012 Y1 - 2012/11/01 TI - A NEW METHOD FOR INVESTIGATION AND RECOGNIZING OF SELF-ADJOINT BOUNDARY VALUE PROBLEMS TT - روش جدید برای بررسی و تشخیص خودالحاق بودن مسایل مقدار مرزی شامل معادلات دیفرانسیل عادی N2 - Boundary value problems (BVPs) are one of the most important fields in engineering and mathematical physics. In self-adjoint case of these problems, there are some facilities to solve them, such as eigenvalues of adjoint equations are real numbers and associated eigenfunctions make an orthogonal basis system. In this paper a new method for investigation of self-adjoint B.V.Ps including ordinary differential equations (O.D.Es) is introduced. Based on this method, at first, some necessary conditions are obtained by making use of fundamental solutions of adjoint equations. Then an algebraic system is made by this necessary conditions and boundary conditions of given boundary value problem. Finally, by making use of Lagrangian identity and boundary values of unknown function, sufficient conditions for having a self-adjoint problem are presented. SP - 295 EP - 304 AU - Jahanshahi, Mohammad AU - Sajjadmanesh, Mojtaba AD - Azarbayjan University of Tarbiat Moallem KW - Boundary value problem KW - Self-adjoint equation KW - necessary conditions KW - fundamental solution UR - http://jsci.khu.ac.ir/article-1-1453-en.html ER -