What is a Square Root?
The square root of a number $x$ is a value $y$ such that $y^2 = x$. In other words, it is a number that, when multiplied by itself, gives the original number.
For example, the square root of 9 is 3, because $3 \times 3 = 9$. The symbol for square root is $\sqrt{x}$, called the radical sign.