Аннотация
In this paper, we consider the question on computation of eigenvalues and eigenfunctions of a third-order composite type equation in a rectangular region D of the space W 3 2 (0, 1) satisfying the following boundary conditions u| ∂D = 0, u x (0, y) = u x (1, y) , u y (x, 0) = u y (x, 1) , where D = {x, y : 0 < x < 1, 0 < y < 1}.All eigenvalues and eigenfunctions of the considered spectral problem are found, and the adjoint operator is constructed.