NEW HERE? LEARN MORE
closeclose
Last visit was: 24 Apr 2024, 15:38 It is currently 24 Apr 2024, 15:38
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

if x<0, what is the value of ^1/4+(-x*|x|)^1/2 i guess

User avatar
MA
Director
Director
Joined: 25 Nov 2004
Posts: 707
Own Kudos [?]: 448 [0]
Given Kudos: 0
Send PM
if x<0, what is the value of ^1/4+(-x*|x|)^1/2 i guess [#permalink] New post   18 Jul 2006, 14:40
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Hide Show timer Statistics
if x<0, what is the value of [(x-3)^4]^1/4+(-x*|x|)^1/2

i guess it was discussed earlier. no OA.



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
paddyboy
Senior Manager
Senior Manager
Joined: 06 May 2006
Posts: 388
Own Kudos [?]: 77 [0]
Given Kudos: 2
Send PM
Re: if x<0, what is the value of ^1/4+(-x*|x|)^1/2 i guess [#permalink] New post   18 Jul 2006, 15:12
Answer is 3 - 2x?

Using the newly learnt lesson that the root of any positive integer is its absolute value (which is positive).

Going by this logic, [(x-3)^4]^1/4 evaluates to (-x+3); and sqrt(-x|x|) evalutates to -x.

So we get (-x + 3) - x = 3 - 2x :shock:
User avatar
freetheking
Manager
Manager
Joined: 22 May 2006
Posts: 188
Own Kudos [?]: 944 [0]
Given Kudos: 0
Location: Rancho Palos Verdes
Send PM
Re: if x<0, what is the value of ^1/4+(-x*|x|)^1/2 i guess [#permalink] New post   18 Jul 2006, 17:33
paddyboy wrote:
Answer is 3 - 2x?

Using the newly learnt lesson that the root of any positive integer is its absolute value (which is positive).

Going by this logic, [(x-3)^4]^1/4 evaluates to (-x+3); and sqrt(-x|x|) evalutates to -x.

So we get (-x + 3) - x = 3 - 2x :shock:


We can plug in any integer to check the ans.

if X = -1
[(-1-3)^4]^1/4+(1*|-1|)^1/2 = 5

3-2x = 3+2 = 5

So, we know 3-2x is correct!
User avatar
rajiv_av
Intern
Intern
Joined: 20 Jun 2005
Posts: 25
Own Kudos [?]: 1 [0]
Given Kudos: 0
Location: Santa Clara
Send PM
Re: if x<0, what is the value of ^1/4+(-x*|x|)^1/2 i guess [#permalink] New post   18 Jul 2006, 18:34
[(x-3)^4]^1/4 how does it evaluate to -x+3??


I thought 4 and 1/4 cancelled themselves.
User avatar
freetheking
Manager
Manager
Joined: 22 May 2006
Posts: 188
Own Kudos [?]: 944 [0]
Given Kudos: 0
Location: Rancho Palos Verdes
Send PM
Re: if x<0, what is the value of ^1/4+(-x*|x|)^1/2 i guess [#permalink] New post   18 Jul 2006, 18:37
rajiv_av wrote:
[(x-3)^4]^1/4 how does it evaluate to -x+3??


I thought 4 and 1/4 cancelled themselves.


but we are given that x<0..

if you cancelled 4 and 1/4, you get |x-3| not x-3..


So x-3<0... |x-3| = -x+3
User avatar
ywilfred
SVP
SVP
Joined: 07 Jul 2004
Posts: 2004
Own Kudos [?]: 1899 [0]
Given Kudos: 0
Location: Singapore
Send PM
Re: if x<0, what is the value of ^1/4+(-x*|x|)^1/2 i guess [#permalink] New post   18 Jul 2006, 19:10
[(x-3)^4]^1/4+(-x*|x|)^1/2

-x+3 + (-x*|x|)^1/2

-x+3 + (x^2)^1/2

-x+3-x
-2x+3


We have to invert the signs because x is negative...



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: if x<0, what is the value of ^1/4+(-x*|x|)^1/2 i guess [#permalink]
18 Jul 2006, 19:10
Moderators:
Bunuel
Math Expert
92900 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions