Approximations of Sturm–Liouville eigenvalues using differential quadrature (DQ) method

The polynomial-based differential quadrature (PDQ) and the Fourier expansion-based differential quadrature (FDQ) methods are applied in this work to compute eigenvalues of the Sturm–Liouville problem. It is demonstrated through some examples that accurate results for the first k th eigenvalues of the problem, where k = 1 , 2 , 3 , … , can be obtained by using (at least) 2 k mesh points. The results of this work are compared with other published results in the literature.