|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
25%
(medium)
Question Stats:
76% (01:17) correct
24%
(02:15)
wrong
based on 473
sessions
History
Date
Time
Result
Not Attempted Yet
If f is the function defined by \(f(x) = x^2*(1-x)^2\) for all x, then f(1-x) =
A. f(x)
B. f(x)^2
C. 1 - f(x)
D. (1-x)*f(x)
E. f(1) - f(x)
A. f(x)
B. f(x)^2
C. 1 - f(x)
D. (1-x)*f(x)
E. f(1) - f(x)
03 Sep 2011, 09:35
Kudos
Bookmarks
petercao
\(f(x) = x^2 (1-x)^2\)
What is \(f(1-x)\)?
Just replace x with (1-x)
\(f(1-x) = (1-x)^2 (1-(1-x))^2\)
\(f(1-x) = (1-x)^2 (x)^2\)
\(f(1-x) = (x)^2(1-x)^2 = f(x)\)
Ans: "A"
********************************
Or pick x=3; 1-x=1-3=-2
\(f(1-x)=f(-2)=(-2)^2*(1-(-2))^2=4*9=36\)
Let's check each option separately:
A. f(x)
\(f(3)=3^2*(1-3)^2=9*4=36\). Holds good. Possible answer.
B. [f(x)]^2
\((36)^2\). Ignore
C. 1 - f(x)
\(1-36=-35\). Ignore
D. (1-x) f(x)
\((1-3)(36)=36*-2=-72\). Ignore
E. f(1) - f(x)
\(1^2*(1-1)^2-36=0-36=-36\). Ignore.
Only A gave us what we got with f(1-x) i.e. f(-2).
Ans: "A"
General Discussion
