Closed-form solutions are derived for some improper integrals used in the Kobayashi Potential (KP) method, using the calculus of residues. These integrals are categorized as waveguiding and radiating, which are single-valued and double-valued, respectively. Both classifications are considered for interior and exterior regions, with respect to the discontinuous boundary. Fourier functional space is used to facilitate contour integration for interior problems. It has been demonstrated that radiating integrals are a limiting case of waveguiding integrals. Therefore, the same strategy can be applied to both types of integrals.