m MATINFAR
Hamideh Abdollahi lashaki
a RIAHIFAR

In this paper, we present a matrix method to solve in- nite boundary integro-di erential equations (IBI-DE) of the sec-ond kind in terms of Laguerre polynomials. Properties of thesepolynomials and operational matrix of integration are rst pre-sented. These properties are then used to transform the integralequation to a matrix equation which corresponds to a system linearof algebraic equations with unknown Laguerre coe cients.