(1) Even root number 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.

The root sign is a mathematical symbol. 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. The n-th handwritten and printed characters are represented by, and the number of roots or algebraic expressions are written in the area surrounded by the left side of the symbol and the right side of the horizontal part above the symbol, which cannot be out of bounds.

Extended data

The history of the root sign—

It was not until17th century that the French mathematician Descartes (1596 ~ 1650) first used the radical sign "√ ~". In a book, Descartes wrote: "If you want to find the square root of n, write it;" If you want to find the cube root of n, just write. "

Sometimes there are many terms in the square root. In order to avoid confusion, Descartes connected these terms with a horizontal line, and added the root sign √ ~ in front of it (but there is a small hook more than Rudolph's root sign), which is the current root sign form.

Cubic root symbols appeared very late, and it was not until the eighteenth century that we saw the use of symbols in a book, such as the cube root of 25. Later, such as √ ~, radical symbols gradually began to be used.