c++ program

C++ has a standard function to compute the square root of a number, but there is no similar function for computing the cubic root. The cubic root x 1/3 of a real number x can be computed using an iterative method called Newton's Method. In this method we start with an initial guess Y for the cubic root, and then iteratively compute better approximations using the formula: Ynew-Y-[Y * Y-x/Y] / [ 2 Y + x/ (Y * Y)] for k = 0, 1, 2, ....? We stop and accept the value of Ynew when it differs from the previous value by an error less than a certain tolerance e ( e.g. e = 0.00001) , ie. when I Ynew-YI / Y