Square Roots

In mathematics, a square root of a number is a value that, when multiplied by itself, gives the original number. For example, both 3 and -3 are square roots of 9 because 

3×3=9 and 

−3×−3=9.

Every positive number has two square roots: one positive and one negative. The positive square root is often referred to as the principal square root and is denoted by 

x

​

. The negative square root is denoted by 

−

x

.

The square root of a number is the inverse operation of squaring a number. Squaring a number means multiplying the number by itself, while finding the square root involves determining which number, when multiplied by itself, yields the original number.

For instance, the square root of 16 is both 4 and -4, since 42=16 and (−4)2=16.