..... Math 9 Projects .....

Mathematics 9 STUDENT PROJECTS Square Roots by Zain L.
The principal square root is the positive square root of a number.

... even though both 2² = 4 and (-2)² = 4

You cannot find the square root for a negative number; there is no answer for that.
For example:

Here are some more examples:

Content, Graphics, & Design by WCS Grade 9 students, 2000