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

 It is currently 22 May 2015, 23:26

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# For which of the following functions f is f(x) = f(1-x) for

Author Message
TAGS:
Manager
Joined: 11 Apr 2008
Posts: 129
Location: Chicago
Followers: 1

Kudos [?]: 39 [0], given: 0

For which of the following functions f is f(x) = f(1-x) for [#permalink]  18 Aug 2008, 12:58
For which of the following functions f is f(x) = f(1-x) for all x?
A) f(x) = 1-x
B) f(x) =1 - (x^2)
C) f(x) = x^2 - (1-x)^2
D) f(x) = x^2 * (1-x)^2
E) f(x) = x/(1-x)
_________________

Factorials were someone's attempt to make math look exciting!!!

SVP
Joined: 07 Nov 2007
Posts: 1828
Location: New York
Followers: 29

Kudos [?]: 551 [0], given: 5

Re: f(x) mess [#permalink]  18 Aug 2008, 13:02
brokerbevo wrote:
For which of the following functions f is f(x) = f(1-x) for all x?
A) f(x) = 1-x
B) f(x) =1 - (x^2)
C) f(x) = x^2 - (1-x)^2
D) f(x) = x^2 * (1-x)^2
E) f(x) = x/(1-x)

D
f(x) = x^2 * (1-x)^2
f(1-x)= (1-x)^2 * (1-(1-x))^2)=(1-x)^2 * x^2=f(x)
_________________

Smiling wins more friends than frowning

Manager
Joined: 11 Apr 2008
Posts: 129
Location: Chicago
Followers: 1

Kudos [?]: 39 [0], given: 0

Re: f(x) mess [#permalink]  18 Aug 2008, 13:17
x2suresh wrote:
brokerbevo wrote:
For which of the following functions f is f(x) = f(1-x) for all x?
A) f(x) = 1-x
B) f(x) =1 - (x^2)
C) f(x) = x^2 - (1-x)^2
D) f(x) = x^2 * (1-x)^2
E) f(x) = x/(1-x)

D
f(x) = x^2 * (1-x)^2
f(1-x)= (1-x)^2 * (1-(1-x))^2)=(1-x)^2 * x^2=f(x)

But if x = 3 (for example)-->
f(x) ---> f(3) = 3^2 * (1-3)^2 ---> 9 * 4 = 36
f(1-x) ---> f(1-3) = -2^2 * (-2-3)^2 ---> 4 * 25 = 100

It does not work b/c 36 does not equal 100. Could someone please explain.
_________________

Factorials were someone's attempt to make math look exciting!!!

SVP
Joined: 07 Nov 2007
Posts: 1828
Location: New York
Followers: 29

Kudos [?]: 551 [0], given: 5

Re: f(x) mess [#permalink]  18 Aug 2008, 13:29
brokerbevo wrote:
x2suresh wrote:
brokerbevo wrote:
For which of the following functions f is f(x) = f(1-x) for all x?
A) f(x) = 1-x
B) f(x) =1 - (x^2)
C) f(x) = x^2 - (1-x)^2
D) f(x) = x^2 * (1-x)^2
E) f(x) = x/(1-x)

D
f(x) = x^2 * (1-x)^2
f(1-x)= (1-x)^2 * (1-(1-x))^2)=(1-x)^2 * x^2=f(x)

But if x = 3 (for example)-->
f(x) ---> f(3) = 3^2 * (1-3)^2 ---> 9 * 4 = 36
f(1-x) ---> f(1-3) = -2^2 * (-2-3)^2 ---> 4 * 25 = 100

It does not work b/c 36 does not equal 100. Could someone please explain.

Please check the highlighted part.. you are doing wrong.

f(1-x) ---> f(1-3) =f(-2) = -2^2 * (1-(-2))^2 ---> 4 * (-3)^2 = 36
_________________

Smiling wins more friends than frowning

Manager
Joined: 11 Apr 2008
Posts: 129
Location: Chicago
Followers: 1

Kudos [?]: 39 [0], given: 0

Re: f(x) mess [#permalink]  18 Aug 2008, 13:52
x2suresh wrote:
brokerbevo wrote:
x2suresh wrote:

But if x = 3 (for example)-->
f(x) ---> f(3) = 3^2 * (1-3)^2 ---> 9 * 4 = 36
f(1-x) ---> f(1-3) = -2^2 * (-2-3)^2 ---> 4 * 25 = 100

It does not work b/c 36 does not equal 100. Could someone please explain.

Please check the highlighted part.. you are doing wrong.

f(1-x) ---> f(1-3) =f(-2) = -2^2 * (1-(-2))^2 ---> 4 * (-3)^2 = 36

Woops. Thanks for that catch.
_________________

Factorials were someone's attempt to make math look exciting!!!

Re: f(x) mess   [#permalink] 18 Aug 2008, 13:52
Similar topics Replies Last post
Similar
Topics:
2 For which of the following functions f is f(x) = f(1-x) for 15 28 Jun 2011, 07:12
For which of the following functions f is f(x) = f(1- x) for 3 29 Sep 2006, 18:24
For which of the following functions f is f(x) = f(1-x) for 1 06 Apr 2006, 14:17
For which of the following functions f is f(x) = f(1 - x) 11 22 Jan 2006, 22:57
For which of the following functions f is f(x) = f(1 - x) 6 21 Aug 2005, 18:27
Display posts from previous: Sort by