2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27575Spin correlation functions (up to the 3-site one) of disordered Ising model with the nearest neighbour interaction are calculated and investigated within a two-site cluster approximation for both quenched and annealed cases. The approach yields the exact results for the one-dimensional system. The long-range interaction is taken into account in the mean field approximation.19 (small) pages, lplain emtex with emlines, fancyhea, twoside; pcx figuresCondensed Mattertext