Analytic and numerical solution of coupled implicit semi-infinite diffusion problems

This paper deals with singular coupled implicit semi-infinite mixed diffusion problems. By application of the sine Fourier transform, existence conditions and an analytic closed form solution is first obtained. Given an admissible error and a rectangular bounded closed domain, analytic-numerical approximations whose error with respect to the exact solution is less than the admissible error in the bounded domain are constructed. An algorithm and an illustrative example are included.