The square root of a number can never be negative. That is not what is happening here, though - if x is negative, as we're told at the beginning of the question, then -x is positive.JeetGulia wrote:IF X<0, then sq root of -X*lXl is
A) -X
B) -1
C) 1
D) X
E) Sq Root X.
Ans is -X, How can square root of number be -ve?
Value of X
This topic has expert replies
Source: Beat The GMAT — Problem Solving |
GMAT/MBA Expert
-
Ian Stewart
- GMAT Instructor
- Posts: 2623
- Joined: Mon Jun 02, 2008 3:17 am
- Location: Montreal
- Thanked: 1090 times
- Followed by:355 members
- GMAT Score:780
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com
ianstewartgmat.com
ianstewartgmat.com
-
[email protected]
- Junior | Next Rank: 30 Posts
- Posts: 23
- Joined: Sun Aug 15, 2010 9:58 pm
The way i understand it:
X<0
let's consider X to be -5.
therefore, the solution for the equation: -X*(X) is:
-(-5) * (-5)= 5*5=25. so, sqaure root of this is either -5 or 5.
since it is given that X is less than 0, it ought to be -5.
X<0
let's consider X to be -5.
therefore, the solution for the equation: -X*(X) is:
-(-5) * (-5)= 5*5=25. so, sqaure root of this is either -5 or 5.
since it is given that X is less than 0, it ought to be -5.
