Square roots

[aparajit.rajan]

This is a general question. if X is a positive number, say X=2, then is sqrt(x) also a positive number, or it can be both positive and negative.

Thanks. :)

[RonPurewal]

This is a general question. if X is a positive number, say X=2, then is sqrt(x) also a positive number, or it can be both positive and negative.

Thanks. :)

the "√" sign represents only the positive square root. always, forever, no exceptions ever.
this is not just a gmat thing, by the way; this is the universal meaning of the "√" sign, everywhere in the world where standard mathematical notation is used.

(if you care about why, just think of how useless the "√" sign would be if it could stand for either sign!
for instance... how long is the diagonal of a square whose side length is 1?
if you said "√2", then you're right -- but the only reason you can write "√2" there is that you know it's the positive value. if "√" could stand for either positive or negative, then it would actually be impossible to write the length of the diagonal.)