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

It is currently 31 Jul 2015, 23:05
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

Challenge 25: 19

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
avatar
Joined: 03 Jul 2006
Posts: 178
Followers: 1

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

Challenge 25: 19 [#permalink] New post 13 Jul 2006, 05:49
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Can someone please explain this

Q 19)

|X/2|+|Y/2|=5 encloses a region. Find its area
Intern
Intern
User avatar
Joined: 11 Jul 2006
Posts: 37
Location: Boston
Followers: 0

Kudos [?]: 1 [0], given: 0

Re: Challenge 25: 19 [#permalink] New post 13 Jul 2006, 07:47
The given equation translates to 4 equations,
Y = x + 10
Y = -x + 10
Y = x – 10
Y = -x- 10

The area enclosed by these 4 lines is a square, with the X and Y intercepts being 10 on all axis. Therefore the side of the square is 10*2^(1/2). The area is this translates to 200


Cheers,
Anand
rkatl wrote:
Can someone please explain this

Q 19)

|X/2|+|Y/2|=5 encloses a region. Find its area
Manager
Manager
avatar
Joined: 03 Jul 2006
Posts: 178
Followers: 1

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

thanks [#permalink] New post 13 Jul 2006, 08:29
thanks a lot.. that helps.

Can you help me with this too ?

how many roots does it have ?
sqrt(x^2+1)+sqrt(x^+2)=2

When I do it algebrically it seem have 4 roots. But the answer is 0.
Not sure if I making any mistake in assuming the no. roots for an equation
with x power 4.
Manager
Manager
avatar
Joined: 03 Jul 2006
Posts: 178
Followers: 1

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

 [#permalink] New post 13 Jul 2006, 08:30
btw, the explaination given for the above problem is

This equation has no roots. sqrt(x^2 + 1) is bigger than or equal to 1, sqrt(x^2 + 2) is bigger than or equal to sqrt(2). Therefore, sqrt(x^2 + 1) + sqrt(x^2 + 2) is bigger than or equal to 1 + sqrt(2), which is bigger than 2.

I can't seem to understand this logic.
Intern
Intern
User avatar
Joined: 11 Jul 2006
Posts: 37
Location: Boston
Followers: 0

Kudos [?]: 1 [0], given: 0

 [#permalink] New post 13 Jul 2006, 12:09
What I understand is you are trying to square these terms and arrive at an equation which is of the nature x^4, which leads you to believe that it has 4 roots. However, that is not always the case, any equation of the nature x^n will have n roots, but for these to be real it would have to satisfy some condition. If it does not then the roots are imaginary. That applies to the expression you get. However I am not sure what that condition is for an expression of the 4th order.
Hope this helps.
-------

rkatl wrote:
btw, the explaination given for the above problem is

This equation has no roots. sqrt(x^2 + 1) is bigger than or equal to 1, sqrt(x^2 + 2) is bigger than or equal to sqrt(2). Therefore, sqrt(x^2 + 1) + sqrt(x^2 + 2) is bigger than or equal to 1 + sqrt(2), which is bigger than 2.

I can't seem to understand this logic.
  [#permalink] 13 Jul 2006, 12:09
Display posts from previous: Sort by

Challenge 25: 19

  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®.