Find all School-related info fast with the new School-Specific MBA Forum

It is currently 16 Sep 2014, 23:34

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

SQUARE ROOT

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 14 May 2006
Posts: 32
Followers: 0

Kudos [?]: 0 [0], given: 0

SQUARE ROOT [#permalink] New post 22 Jul 2006, 12:07
If x<0 then (-x|x|)^1/2 =?

The answer is -x.
My ques is why not x both are choices.

Pravin
CEO
CEO
User avatar
Joined: 20 Nov 2005
Posts: 2922
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD - Class of 2008
Followers: 15

Kudos [?]: 80 [0], given: 0

GMAT Tests User
 [#permalink] New post 22 Jul 2006, 12:11
discussed recently. Very good question.

http://www.gmatclub.com/phpbb/viewtopic.php?t=32092
_________________

SAID BUSINESS SCHOOL, OXFORD - MBA CLASS OF 2008

Senior Manager
Senior Manager
avatar
Joined: 22 May 2006
Posts: 375
Location: Rancho Palos Verdes
Followers: 1

Kudos [?]: 16 [0], given: 0

GMAT Tests User
Re: SQUARE ROOT [#permalink] New post 22 Jul 2006, 12:21
pravinkawadkar wrote:
If x<0 then (-x|x|)^1/2 =?

The answer is -x.
My ques is why not x both are choices.

Pravin


GMAT doesn't cover imaginary numbers!!
Thus, sqrt(?) > 0 always!! also ? > 0 always!!

(-x*-x)^1/2 = (x^2)^1/2 = -x
if you not sure, try to plug in any negative interger. ex. -1
given eq.
(1*1)^1/2 = 1 : -x = -(-1) = 1
_________________

The only thing that matters is what you believe.

Director
Director
User avatar
Joined: 28 Dec 2005
Posts: 761
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
 [#permalink] New post 22 Jul 2006, 14:43
it would help if you posted the question in its entirety :)

Nice link, ps_dahiya....something new:

Let me see if I understand it correctly -

(-x|x|)^1/2 is our expression, and x is negative.

From the answer choices, the others are clearly out apart from x and -x. If x is the root, then we get the expression as sqrt (-(x).x)^1/2, which is the square root of a negative number. By definition this is impossible.

If the root is -x, then we get the expression as sqrt(-(-x).x)^1/2 which is the sqrt of a +ve number.

Ok
  [#permalink] 22 Jul 2006, 14:43
    Similar topics Author Replies Last post
Similar
Topics:
Square root pmenon 8 14 Oct 2008, 23:12
Square roots vksunder 5 03 Oct 2008, 11:06
square root lan583 5 25 Aug 2006, 07:27
Squares and Roots ccax 3 26 Apr 2006, 07:27
Square root yb 4 24 Nov 2005, 15:54
Display posts from previous: Sort by

SQUARE ROOT

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.