for cube roots of a positive number, it could have a real number of a negative number but has to contain 2 negatives if it does and one positive. Eg. (-)*(-)* (+) = +
0.001 can be made by multiplying 3 0.1's (0.1^3)
However, we are finding the root here so my explanation above tells us that a cuberoot of a positive number is never a negative.
So the answer is 0.1