The square root is also called quadratic square root, which is expressed as √ ~ The square root that belongs to non-negative number is called arithmetic square root. Positive numbers have two real square roots in opposite directions; 0 has only one square root, which is 0 itself; The square root of a pure imaginary number with two yokes.

Generally speaking, "√ ~" is only used to represent the arithmetic square root, that is, a non-negative square root. For example, the mathematical language is √ ~ 16 = 4. The language description is: under the root sign 16=4.

If the cube of a number is equal to A, then this number is called the cube root of A, which means that if X? =a, then x is called the cube root of a.

Warm reminder that the root index 2 in the square root can be omitted, but the root index 3 in the cube root cannot be omitted.