Hi infiniti007,
This question is really more about the 'thoroughness' of your thinking than anything else. Most Test Takers would look at this question and think "Oh, the answer is obviously X=1....", but is that really the ONLY answer???
The numbers -1, 0 and 1 have all sorts of interesting 'impacts' on how various math rules 'work', so it's important to keep them in mind as you work through the Quant section of the GMAT.
Here, we're asked what MUST be true based on the equation √x = x. You should be able to determine the 2 solutions to this equation (whether you do the formal algebra or not). Those solutions are 0 and 1. Using those answers as reference, only one of the 5 answers choices is correct...
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
