Page "Square root" Paragraph 3

Every positive number a has two square roots:, which is positive, and, which is negative.

Together, these two roots are denoted ( see ± shorthand ).

Although the principal square root of a positive number is only one of its two square roots, the designation " the square root " is often used to refer to the principal square root.

For positive a, the principal square root can also be written in exponent notation, as a < sup > 1 / 2 </ sup >.