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reply2spg · 2009 October 29th, 12:10 AM

If x < 0, then √(-x│x│) is

A. -x
B. -1
C. 1
D. x
E. √x

SPOILER: OA D IMO A

xperience · 2009 October 29th, 08:57 AM

Quote:

Originally Posted by reply2spg

If x < 0, then √(-x│x│) is

A. -x
B. -1
C. 1
D. x
E. √x

SPOILER: OA D IMO A

The modulus of a negative number is negative.

hence

√(-x│x│) = √(-x)*(-x) = √x^2

= x (it's the positive square root)

hence D is correct.

Regards,
Anubhav

eravi11 · 2009 October 30th, 04:37 AM

OA is wrong..not sure if u picked up from sets
answer has to be A.

I got this y'day in gprep..and A is correct answer

touche · 2009 October 30th, 06:22 AM

IMO D is clear.....
let x=-3
then, √(-x│x│) = √-(-3)*3= √9=3=x
xperience, I did not understand-"The modulus of a negative number is negative"
can you explain please! thanks!

Rishav · 2009 October 31st, 09:23 AM

Agree with D

finsisher · 2009 October 31st, 07:05 PM

OA is wrong answer should be A

touche · 2009 October 31st, 07:26 PM

Quote:

Originally Posted by finsisher

OA is wrong answer should be A

Pray explain finisher, for lesser mortals!
thanks

MBAchase · 2009 November 1st, 04:04 AM

Yes the answer should be (A).

finsisher · 2009 November 1st, 08:25 AM

Quote:

Originally Posted by touche

IMO D is clear.....
let x=-3
then, √(-x│x│) = √-(-3)*3= √9=3=x
xperience, I did not understand-"The modulus of a negative number is negative"
can you explain please! thanks!

Ok
u have assumed x = -3 aint you?

then how are you confirming that x =3 in line 2? in fact -x =3 so A is correct

touche · 2009 November 1st, 10:14 AM

OK! thanks finisher for showing the lights!

2009 October 29th, 12:10 AM	#1 (permalink)
reply2spg TestMagic Guru-in-Training Join Date: Jan 2009 Posts: 551	Sq. Root If x < 0, then √(-x│x│) is A. -x B. -1 C. 1 D. x E. √x SPOILER: OA D IMO A

2009 October 30th, 06:22 AM	#4 (permalink)
touche Within my grasp! Join Date: Jun 2009 Location: mumbai Posts: 292	IMO D is clear..... let x=-3 then, √(-x│x│) = √-(-3)*3= √9=3=x xperience, I did not understand-"The modulus of a negative number is negative" can you explain please! thanks! _ _ _ _ SIG _ _ _ _ Looking high and Low

2009 November 1st, 04:04 AM	#8 (permalink)
MBAchase GMAT TEST EXPERTS Join Date: Nov 2008 Posts: 520	Yes the answer should be (A). _ _ _ _ SIG _ _ _ _ Get your free profile evaluation with our proprietary spider plot: http://mbachase.co/index.php?option=com_content&view=article&id=72&It emid=62

2009 November 1st, 10:14 AM	#10 (permalink)
touche Within my grasp! Join Date: Jun 2009 Location: mumbai Posts: 292	OK! thanks finisher for showing the lights! _ _ _ _ SIG _ _ _ _ Looking high and Low

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2009 October 30th, 04:37 AM	#3 (permalink)
eravi11 So far So bad! Join Date: Feb 2009 Posts: 630	OA is wrong..not sure if u picked up from sets answer has to be A. I got this y'day in gprep..and A is correct answer

2009 October 31st, 09:23 AM	#5 (permalink)
Rishav I JUST got here. Join Date: Sep 2009 Posts: 11	Agree with D

2009 October 31st, 07:05 PM	#6 (permalink)
finsisher TestMagic Guru Join Date: Feb 2007 Posts: 1,845	OA is wrong answer should be A

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