Radical symbol

In mathematics, the radical symbol, radical sign, root symbol, or surd is a symbol for the square root or higher-order root of a number. The square root of a number x is written as

${\displaystyle {\sqrt {x}},}$

while the nth root of x is written as

${\displaystyle {\sqrt[{n}]{x}}.}$

It is also used for other meanings in more advanced mathematics, such as the radical of an ideal.

In linguistics, the symbol is used to denote a root word.