Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 25 May 2017, 13:29

### 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
Manager
Joined: 11 Apr 2008
Posts: 128
Location: Chicago
Followers: 1

Kudos [?]: 54 [0], given: 0

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

### Show Tags

18 Aug 2008, 13:58
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

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: 1806
Location: New York
Followers: 38

Kudos [?]: 931 [0], given: 5

### Show Tags

18 Aug 2008, 14:02
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: 128
Location: Chicago
Followers: 1

Kudos [?]: 54 [0], given: 0

### Show Tags

18 Aug 2008, 14:17
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: 1806
Location: New York
Followers: 38

Kudos [?]: 931 [0], given: 5

### Show Tags

18 Aug 2008, 14:29
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: 128
Location: Chicago
Followers: 1

Kudos [?]: 54 [0], given: 0

### Show Tags

18 Aug 2008, 14:52
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, 14:52
Display posts from previous: Sort by