Square root means that for any nonnegative real number B, there is a nonnegative real number A, which makes A? =b, then this non-negative real number A is the square root of B, and the symbol is B under the root sign.
The root sign is a mathematical symbol. The root sign is a symbol used to represent the root operation of a number or an algebra. If a? =b, then a is the n-th root of b or a is the 1/n power of b.
In ancient times, Egyptians used the symbol ┌ to represent the square root. Indians write ka in front of the square root number. Arabs use this expression.
Around 1840, the Germans used the dot "."to represent the square root, two dots "…" to represent the square root of degree 4, and three dots "…" to represent the cube root. For example, .3, ...3, ... 3 represent the square root, quartic square root and cubic root of 3, respectively.
At the beginning of the16th century, perhaps because of the fast writing speed, the dot had a slender tail and became "√ ~". 1525, Rudolf adopted the radical sign for the first time in his algebra works. For example, he wrote that 4 is 2 and 9 is 3, but this writing method has not been generally recognized and adopted.