Represents the arithmetic square root of an internal number.

The root number x, the domain of x is a nonnegative real number. In other words, the root sign only makes sense when x is a real number and not less than 0.

Y= root number X.

Let the square of a number y = x.

If x=0, y can only be 0. So the root number 0=0.

If x is greater than 0, we know that there are two y's that satisfy the condition. They are all real numbers and reciprocal. That is to say, a positive and a negative. They are called the square root of x, and positive ones are called arithmetic square roots.

To sum up: y= the root sign x represents a non-negative real number y that satisfies y =x (x belongs to a non-negative real number).

A nonnegative real number x corresponds to and only corresponds to a nonnegative real number yRT that is a right angle.