The root sign is a symbol used to represent the root operation of a number or an algebra. If an n = b, then a is the n-th square 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 or algebraic expression of roots is written in the area surrounded by the right side of the V-shaped part on the left side of the symbol and the lower part of a horizontal part above the symbol, which can be out of bounds; The power of n is written on the left side of the symbol √ ~ When n=2, n can be ignored. If the root number or algebra is too long, the upper column must be extended to ensure that the root number or algebra below is covered.

In fact, it is the inverse operation of the square number.