the root of factor
root ( expression )
Factor and expression yield lists of integers, numbers, or complexes.
The root function returns the value of the nested radicals represented by the numeric values passed to it. For example, root(9,8,3) evaluates to 9^(1/(8^(1/3))) or 3.
If all the values are integers or numbers, a number is returned. If any value is a complex, a complex is returned.