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

It is currently 03 Sep 2015, 20:06
GMAT Club Tests

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

unsolved challenge problem

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Director
Director
User avatar
Joined: 09 Aug 2006
Posts: 525
Followers: 2

Kudos [?]: 45 [0], given: 0

unsolved challenge problem [#permalink] New post 22 Jul 2007, 04:58
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Hi Guys,
the problem in below has not reached a conclusion on why E is wrong. could anyone help..


http://www.gmatclub.com/phpbb/viewtopic ... =challenge
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesGMAT Pill GMAT Discount Codes
Manager
Manager
avatar
Joined: 08 Jul 2007
Posts: 174
Followers: 1

Kudos [?]: 5 [0], given: 0

 [#permalink] New post 22 Jul 2007, 06:00
function f (x) SATISFIES f (x) =f (x)^2 FOR ALL x which of the following must be true


f(4) = f(2)*f(2)
f(16) - f(-2) = 0
f(-2) + f(4) = 0
f(3) = 3*f(3)
f(0) = 0

E is not necessarily true. It depends on the function. For example, if the function were such that f(x)=1 for all values of x, then f(x)=f(x)^2 but f(x) does not equal 0. Does that make sense? We have no function so we can't assume that f(0)=0. f(0) could equal some other value depending on the function.
Director
Director
User avatar
Joined: 14 Jan 2007
Posts: 779
Followers: 2

Kudos [?]: 83 [0], given: 0

 [#permalink] New post 22 Jul 2007, 08:31
No numerical value of f(x) can be derived from the question. Stem states the values of function in terms of function.
Senior Manager
Senior Manager
User avatar
Joined: 28 Jun 2007
Posts: 462
Followers: 2

Kudos [?]: 6 [0], given: 0

 [#permalink] New post 22 Jul 2007, 11:01
Yeah... consider an example:

f(x) = x+1

f(0) != 0.

f(0) = 1.

Though its not one of those examples that satisfies your equation, I guess it proves that the assumption of f(0)=0 is wrong if there is a constant in the equation.
  [#permalink] 22 Jul 2007, 11:01
Display posts from previous: Sort by

unsolved challenge problem

  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®.