In
mathematics, the
nth root of a
number x, where
n is a positive integer, is a number
r which, when raised to the power
n yields
x![](http://bis.babylon.com/?rt=GetFile&uri=!!ARV6FUJ2JP&type=0&index=2599)
where
n is the
degree of the root. A root of degree 2 is called a
square root and a root of degree 3, a
cube root. Roots of higher degree are referred by using ordinal numbers, as in
fourth root,
twentieth root, etc.