# sqrt(16) - how many answers?

By Murray Bourne, 21 Sep 2005

I had a heated debate with some colleagues yesterday when I claimed that √16 = 4. They were strongly advocating that there are 2 answers, ±4.

I pointed out that there is a difference between this question:

Solve for

x:x^{2}= 16

and this question:

Evaluate

x:x= √16.

The first has 2 solutions, the second has one answer.

See the 39 Comments below.