How do you simplify sqrt(9)?

1 Answer
Jul 14, 2015

3

Explanation:

For a given real number a\geq 0, the symbol \sqrt{a} represents the unique non-negative real number whose square is a. That is, (\sqrt{a})^{2}=a.

Since 3^{2}=9 it follows that \sqrt{9}=3.

Proving that \sqrt{a} exists and is unique in the general situation mentioned above from the foundations of arithmetic is actually no easy feat. Take real analysis someday if you want to learn more.