knew how to use compass and straightedge to construct a length equal to the square root of a given length, when an auxiliary line of unit length is given. In 1837 Pierre Wantzel proved that an nth root of a given length cannot be constructed if n is not a power of 2.

Definition and notation

An th root of a number x, where n is a positive integer, is any of the n real or complex numbers r whose nth power is x:

Every

1.Previous
3.Next