... and 3.12,forsufficiently large integer k,weobtain4.32yk,1x sin2kx sinh2kx O1k. 4.40 In similar way, we can seek eigenfunction yk,2x corresponding λk,2 in ... 1967.5 F. S. Rofe-Beketov and A. M. Kholkin, Spectral Analysis of Differential Operators, vol. 7 of World ScientificMonograph Series in Mathematics, World Scientific Publishing, Singapore, 2005.6 ... Boundary Value ProblemsUsing the relations 3.3 and 3.12,forsufficiently large integer k,weobtain4.1yk,1x sin2kx− sinh2kx O1k. 4.10Similarly, since Uj1yυx,...