Square root, also called quadratic root, is expressed as [√￣], where the square root of a non-negative number is called an arithmetic square root. A positive number has two real square roots, which are opposites of each other; 0 has only one square root, which is 0 itself; negative numbers have two conjugate pure imaginary square roots.

Generally, “√￣” is only used to represent arithmetic square roots, that is, non-negative square roots. For example: √16=4.