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GRE Prep Club Team Member
Joined: 20 Feb 2017
Posts: 2508
Given Kudos: 1053
GPA: 3.39
The function f is defined by f(x) = - 1/x for all nonzero numbers x.
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26 Nov 2022, 02:47
26 Nov 2022, 02:47
Expert Reply
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Question Stats:
62% (01:09) correct
37% (00:46) wrong based on 8 sessions
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If a function f is defined by \(f(x)= -\frac{1}{x}\) for all non zero numbers x. If \(f(a) = -\frac{1}{2}\) and \(f(ab) = \frac{1}{6}\) then b= ?
A. 3
B. 1/3
C. -1/3
D. -3
E. -12
A. 3
B. 1/3
C. -1/3
D. -3
E. -12
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Joined: 02 Jan 2020
Status:GRE Quant Tutor
Posts: 1111
Given Kudos: 9
Location: India
Concentration: General Management
Schools: XLRI Jamshedpur, India - Class of 2014
GMAT 1: 700 Q51 V31
GPA: 2.8
WE:Engineering (Computer Software)
Re: The function f is defined by f(x) = - 1/x for all nonzero numbers x.
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09 Dec 2023, 01:04
09 Dec 2023, 01:04
1
\(f(x)= -\frac{1}{x}\)
=> \(f(a)= -\frac{1}{a} = -\frac{1}{2}\) (given)
=> a = 2
\(f(ab) = -\frac{1}{ab} = \frac{1}{6}\)
=> ab = -6
=> 2 * b = -6
=> b = \(\frac{-6}{2}\) = -3
So, Answer will be D
Hope it helps!
Watch the following video to learn the Basics of Functions and Custom Characters
=> \(f(a)= -\frac{1}{a} = -\frac{1}{2}\) (given)
=> a = 2
\(f(ab) = -\frac{1}{ab} = \frac{1}{6}\)
=> ab = -6
=> 2 * b = -6
=> b = \(\frac{-6}{2}\) = -3
So, Answer will be D
Hope it helps!
Watch the following video to learn the Basics of Functions and Custom Characters
General Discussion
GRE Prep Club Team Member
Joined: 20 Feb 2017
Posts: 2508
Given Kudos: 1053
GPA: 3.39
Re: The function f is defined by f(x) = - 1/x for all nonzero numbers x.
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27 Nov 2022, 20:59
27 Nov 2022, 20:59
1
Expert Reply
\(f(x) = \frac{-1}{x}\) ; so \(x = \frac{-1}{f(x)}\)
\(f(a) = \frac{-1}{2}\); so \(a = \frac{-1}{\frac{-1}{2}} = 2\)
\(f(ab) = \frac{1}{6}\); so \(ab = \frac{-1}{\frac{1}{6}} = -6\)
\(b = \frac{-6}{2} = -3\)
Answer: D
\(f(a) = \frac{-1}{2}\); so \(a = \frac{-1}{\frac{-1}{2}} = 2\)
\(f(ab) = \frac{1}{6}\); so \(ab = \frac{-1}{\frac{1}{6}} = -6\)
\(b = \frac{-6}{2} = -3\)
Answer: D
