Question

what is $sqrt{16}$?

Explanation:

Step1: Recall square - root definition

The square - root of a number $x$, denoted as $\sqrt{x}$, is a value $y$ such that $y\times y=x$. We need to find a number $y$ where $y^2 = 16$.
Since $4\times4 = 16$ and $(- 4)\times(-4)=16$, but the principal square - root (denoted by $\sqrt{x}$ for $x\geq0$) is the non - negative root.

Answer:

4