The radical sign is a function operator. There are always the same number of roots as the exponent (two square roots, three cube roots, etc), but since a function can have only one value for each x, we take the radical to mean the primary root, (√16 = 4, but not -4; ³√27 = 3, but not (-1.5 + ½i√3) or (-1.5 - ½i√3)
re(6): Easy solution
