GMAT Prep Question √x^2/x = ?

[rohinivt]

Hi All,
This particular question must have discussed in this forum. But couldn't locate the link.
I got the following question from GMAT Prep.
If x =/ 0, √(x^2)/x =

{=/ means "not equal to"}

A) -1
B) 0
C) 1
D) x
E) |x|/x

I marked C. But the Official Answer is:E
I chose C because, I thought that whatever inside the "√" sign is +ve. So √(x^2) is always +ve x and so the answer is C.

In one of Ron's comments, http://www.manhattangmat.com/forums/posting.php?mode=quote&f=30&p=21193
Ron said "when you have an OPERATOR SYMBOL, such as "√", that symbol will produce exactly ONE value.
for instance, √9 is just 3."

Usually GMAT cannot be wrong. So what is wrong with my logic?
Thanks in Advance.
R

[tim]

x could be negative. In that case you would have a positive divided by a negative, which is never equal to 1. The thing to remember here is that root(x^2) is identically equal to |x|; keep that in mind, because it shows up from time to time..