Question

What is the square root of 256?

Answer 1

`sqrt(256)=16`

at least that's the positive square root

`-16` is also a square root of 256.

`16^2 = (-16)^2 = 256`

By definition, the principal square root of a number is the positive square root. The term "the square root" is commonly used to refer to the principal (positive) root though there are usually two roots.

`sqrt(x^2)=|x|`