Here are some miscellaneous facts about the square root. The check mark symbol for square root is called the "Radical" symbol.
This symbol was first seen in printed form in a paper by Christoph Rudolff back in 1525. As far as we know, the idea itself of square root was probably first expressed by the ancient Babylonians.
In mathematics, a square root of a number a is a number y such that y2 = a; in other words, a number y whose square (the result of multiplying the number by itself, or y⋅y) is a. For example, 4 and −4 are square roots of 16 because 42 = (−4)2 = 16. Every nonnegative real number a has a unique nonnegative square root, called the principal square root, which is denoted by √a, where √ is called the radical sign or radix. For example, the principal square root of 9 is 3, which is denoted by √9 = 3, because 32 = 3 • 3 = 9 and 3 is nonnegative. The term (or number) whose square root is being considered is known as the radicand. The radicand is the number or expression underneath the radical sign, in this example 9