The study of the classical special functions is part of the mathematical analysis and it is all directed to the hypergeometric function and the confluent hypergeometric function, whose differential equations present, respectively, three and two singular points, as well as particular cases, among others we mention, the Jacobi polynomials, depending on three parameters; the Laguerre polynomials and the Whittaker functions, depending on two parameters and the Bessel functions and the Legendre polynomials, depending on a parameter.