Uhm i mean, actually how do we predict the estimated roots before we implement this? Because i wonder if the estimated root is too big enough to predict and sometimes time-consuming, is there any way to predict the roots better and accurate before we implement the Newton Raphson's iterative methods? I am using plain subsitution into the function which sometimes have to check through all the numbers in order to get one estimated root beforehand. Thanks in advance. Regards, Daniel.