“…These orthogonal polynomials, in a real variable t and a complex variable z, have played an important role in applied mathematics, numerical analysis and approximation theory. For this reason, Chebyshev polynomials have been studied extensively, see [8,10,16]. In the study of differential equations, the Chebyshev polynomials of the first and second kinds are the solution to the Chebyshev differential equations (1 − t 2 )y ′′ − ty ′ + n 2 y = 0 (1.1) and (1 − t 2 )y ′′ − 3ty ′ + n(n + 2)y = 0, (1.2) respectively.…”