“…Therefore, and because of their favourable numerical properties (Vlach, 1969;Fox and Parker, 1972;Dahlquist and Bjorck, 1974), the current approach is based upon the expansion of both the state and control in Chebyshev series having unknown coefficients. However, the idea of using both the state and control as independent variables is not new (Canon et al, 1970;Tabak and Kuo, 1971), and polynomial expansion of control and/or state has already been used (Ghonaimy and Bernholtz, 1966;Johnson, 1969;Fegley et al, 1971;Neuman and Sen, 1973;Sirisena, 1973;Nair, 1978).…”