square radical, also called two cube root (math.), expressed as [√￣], where a non-negative number square radical is called an arithmetic square radical. one positive number has two real square radicals, and they are the opposite number of each other; 0 has only one square radical, which is 0 itself; negative number has two conjugate pure imaginary square radicals. Generally, "√￣" is used only to indicate an arithmetic square radical, that is, a non-negative square radical. √16=4.

one positive number has a square radical, then there must be two, and they are the opposite number of each other. Obviously, We know the two square radical one, then we can receive the other square radical in time according to the opposite number concept.