gmat prep question

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gmat prep question

by yvonne12 » Wed Apr 25, 2007 11:32 am
if x<0, then sqrt -X IxI is

why is it -x

I hate absolute values...

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Re: gmat prep question

by jayhawk2001 » Wed Apr 25, 2007 6:52 pm
yvonne12 wrote:if x<0, then sqrt -X IxI is

why is it -x

I hate absolute values...
-x|x| is positive and sqrt of a number is always positive (atleast for
purposes of GMAT). Since x is negative, -x is positive and so
the answer is -x.

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by Cybermusings » Thu Apr 26, 2007 1:33 am
Since x<0, x is to the left of 0 on the number line and hence it's absolute value or IxI will always be -x....
Sample this I -8 I = -(-8 ) = 8
I -17 I = -(-17) = 17
So IxI = -x
and -x * -x = x^2
sqr rt of the number = -x