The root sign is a symbol used to represent the root operation of a number or an algebra. If a? = b, then a is the n-th root of b or a is the 1/n power of b.

Strictly speaking, the root sign represents a nonnegative square root of a nonnegative number. For example, because 2=4 and (-2) = 4, both 2 and -2 are called the square roots of 4, where "2" is represented by √4, that is, √ 4 = 2; And "-2" is represented by -√ 4, that is, -√ 4 =-2.

Value range of the number in the root sign:

In the range of real numbers:

1, the root sign cannot be negative, and its operation result is not negative.

2. It can be negative under odd root sign.

Not limited to real numbers, that is, when considering imaginary numbers, even roots can be negative numbers, and i=√- 1 can be used.