“…where c i are the expansion coefficients with c 0 = 1. The RTE in slab medium with anisotropic scattering has some numerical and rigorous solutions such as: two-flux [4,5], spherical harmonic [6,7], series expansion [8,9,10], integral equation [11,12], Padé approximation [13], iterative [6], variational [11,14,15], eigenfunction expansion [16,17], the linear spline approximation [1], the generalized Eddington approximation [3] and Spectral methods approximation [18,19,20].…”