For non-negative real numbers, the square root is the real number that the result of multiplication is equal to, expressed as ±(√x), which is read as x or the square root of x under the positive and negative square root signs. The non-negative square root is called the arithmetic square root. The square root of a positive integer is usually an irrational number. It can be uniquely defined by the following formula: In fractional exponents, we have: By definition, we know that the square root operation satisfies the distributive law for multiplication, that is: Note that if n is a non-negative real number and when, because it must be a positive number, but there are two solutions, positive and negative. It should be equal to ±; that is (see absolute value).