I know that the square root of a number can be both positive and negative. For instance, square root of 4 can be +2 and -2.
However, in Manhattan GMAT
Prep, Number properties book, it's stated that in GMAT follows the convention that root sign denotes only non-negative root of a number. Therefore, square root of 4 should always resolve to +2 in a GMAT question.
Do you agree with this? I find this hard to believe because I am sure I have solved many Data Sufficiency questions where I considered a square root to have two solutions, positive and negative. Looking forward to what you guys think?