The RAFU method on approximation uses radical functions (RAFU functions) of odd index to approximate an arbitrary function from the knowledge of its values, or its approximate values, at a set of points. The main goal of this book is to show to the scientific community all the results published until now about this approximation procedure Co1, Co2, Co3] in a complete work so that they could be applied in the cases that the researchers consider appropriate to do it. As far as we know, the work is original. It does not impress with the difficulties it overcomes. It does not contain complicated...