GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 18 Oct 2019, 14:43

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.

Close

Request Expert Reply

Confirm Cancel

If f(x) = x/(x + 1), what is f(1/x) in terms of x ?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
SVP
SVP
User avatar
Joined: 21 Jan 2007
Posts: 2254
Location: New York City
If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post Updated on: 25 Sep 2014, 23:28
3
8
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

57% (01:27) correct 43% (01:21) wrong based on 586 sessions

HideShow timer Statistics

If \(f(x) = \frac{x}{x + 1}\), what is \(f(\frac{1}{x})\) in terms of \(f(x)\)?

A. \(f(x)\)
B. \(-f(x)\)
C. \(\frac{1}{f(x)}\)
D. \(1 - f(x)\)
E. none of the above

M19-14

Originally posted by bmwhype2 on 12 Nov 2007, 14:44.
Last edited by Bunuel on 25 Sep 2014, 23:28, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.
Manager
Manager
User avatar
Joined: 01 Sep 2006
Posts: 235
Location: Phoenix, AZ, USA
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 12 Nov 2007, 14:48
bmwhype2 wrote:
F(x) = x/(x+1).
What is f(1/x) in terms of f(x)?

f(x)
-f(x)
1/f(x)
1-F(x)
none of the above

can someone give me a step by step breakdown? I got stuck after 1/(1+x)


f(1/x) = (1/x)/((1/x)+1)==> 1/(1+x)

trying chice D 1-Fx

1- x/(1+x)=== > x+1-x/(1+x)===> 1/(1+x)

so we can see f(1/x)= 1/(1+x) == 1-f(x)

Answe D
Current Student
avatar
Joined: 28 Dec 2004
Posts: 2697
Location: New York City
Schools: Wharton'11 HBS'12
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 12 Nov 2007, 20:52
2
1
after you have broken down to (1/1+x)

test a number, say x=2...

f(2)=2/3

f(1/2)=1/3

which is same as 1-f(x)...

D it is..
Director
Director
avatar
Joined: 09 Aug 2006
Posts: 599
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 12 Nov 2007, 21:31
fresinha12 wrote:
after you have broken down to (1/1+x)

test a number, say x=2...

f(2)=2/3

f(1/2)=1/3

which is same as 1-f(x)...

D it is..


Solved it the same way to get D.
SVP
SVP
User avatar
Joined: 21 Jan 2007
Posts: 2254
Location: New York City
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 15 Nov 2007, 03:16
fresinha12 wrote:
after you have broken down to (1/1+x)

test a number, say x=2...

f(2)=2/3

f(1/2)=1/3

which is same as 1-f(x)...

D it is..


thanks. very helpful
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1749
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 25 Sep 2014, 21:39
3
\(f(x) = \frac{x}{x+1}\)

\(f(\frac{1}{x}) = \frac{\frac{1}{x}}{\frac{1}{x} + 1} = \frac{1}{x+1}\)

\(1 - f(x) = 1 - \frac{x}{x+1} = \frac{1}{x+1}\)

Answer = D
_________________
Kindly press "+1 Kudos" to appreciate :)
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58453
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 25 Sep 2014, 23:31
bmwhype2 wrote:
If \(f(x) = \frac{x}{x + 1}\), what is \(f(\frac{1}{x})\) in terms of \(f(x)\)?

A. \(f(x)\)
B. \(-f(x)\)
C. \(\frac{1}{f(x)}\)
D. \(1 - f(x)\)
E. none of the above

M19-14


\(f(\frac{1}{x})= \frac{\frac{1}{x}}{\frac{1}{x} + 1} = \frac{1}{1 + x} = \frac{1 + x - x}{1 + x} = 1 - \frac{x}{1 + x} = 1 - f(x)\).

Answer: D.

Check other Functions questions in our Special Questions Directory.
_________________
Current Student
User avatar
B
Status: DONE!
Joined: 05 Sep 2016
Posts: 357
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 10 Oct 2016, 15:31
Plug in an value to test out the effect of (1/x) over (x) when fed into the function...

Say x = 3

f(3) = 3/(3+1) = 3/4
f(1/3) = (1/3)/[(1/3)+(3/3)] = 1/4

Thus f(1/x) = 1 - f(x)
Manager
Manager
avatar
B
Joined: 31 Dec 2016
Posts: 65
If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 18 Jul 2017, 21:45
Again a good video if you're having difficulty understanding function notation is here:

https://www.youtube.com/watch?v=T6-Zdr5w_bE
Attachments

gmat function question.png
gmat function question.png [ 273.28 KiB | Viewed 7879 times ]

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13261
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?  [#permalink]

Show Tags

New post 15 Oct 2018, 07:12
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Bot
Re: If f(x) = x/(x + 1), what is f(1/x) in terms of x ?   [#permalink] 15 Oct 2018, 07:12
Display posts from previous: Sort by

If f(x) = x/(x + 1), what is f(1/x) in terms of x ?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne