what number is equal to $sqrt{9}$?

Explanation:

Step1: Recall square - root definition

The square - root of a number (x), (\sqrt{x}), is a value (y) such that (y\times y=x). For (\sqrt{9}), we need to find a number (y) where (y^2 = 9). Since (3\times3 = 9) and ((- 3)\times(-3)=9), but the principal square - root (\sqrt{9}=3).

Answer:

3