Nth root

Summary

In mathematics, an $n$th root of a number $x$ is the number $r$ which, when $n$ copies are multiplied together, yields $x$:

$$r^n = \underbrace{r \times r \times \dotsb \times r}_{n\text{ factors}} = x.$$

The positive integer $n$ is called the index or degree, and the number $x$ of which the root is taken is the radicand. 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. The computation of an $n$th root is a root extraction.