GRE Prep 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.
If f(x) = x2 – 1, what is the value of f(y) + f(–1)?
[#permalink]
25 Jul 2018, 17:12
25 Jul 2018, 17:12
2
Expert Reply
00:00
Question Stats:
92% (00:27) correct
7% (00:58) wrong based on 70 sessions
Hide Show timer Statistics
If \(f(x) = x^2 - 1\), what is the value of \(f(y) + f(-1)\)?
(A) \(y^2 - 1\)
(B) \(y^2\)
(C) \(y^2 + 1\)
(D) \(y^2 - 2y\)
(E) \(y^2 - 2y - 1\)
(A) \(y^2 - 1\)
(B) \(y^2\)
(C) \(y^2 + 1\)
(D) \(y^2 - 2y\)
(E) \(y^2 - 2y - 1\)
Re: If f(x) = x2 – 1, what is the value of f(y) + f(–1)?
[#permalink]
31 Jul 2018, 14:22
31 Jul 2018, 14:22
Expert Reply
Explanation
The question requires plugging y into the function, then plugging –1 into the function, then summing the two results:
\(f(y) = y^2 - 1\)
\(f(-1) = (-1)^2 - 1\)
\(f(-1) = 0\)
Thus, \(f(y) + f(-1) = y^2 - 1 + 0 = y^2 - 1\).
The question requires plugging y into the function, then plugging –1 into the function, then summing the two results:
\(f(y) = y^2 - 1\)
\(f(-1) = (-1)^2 - 1\)
\(f(-1) = 0\)
Thus, \(f(y) + f(-1) = y^2 - 1 + 0 = y^2 - 1\).
Moderator
Joined: 02 Jan 2020
Status:GRE Quant Tutor
Posts: 1141
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)
If f(x) = x2 1, what is the value of f(y) + f(1)?
[#permalink]
03 Dec 2024, 17:50
03 Dec 2024, 17:50
1
\(f(x) = x^2 - 1\) and we need to find the value of \(f(y) + f(-1)\)
To find f(y) we will substitute x with y in \(f(x) = x^2 - 1\)
=> \(f(y) = y^2 - 1\)
Similarly, \(f(-1) = (-1)^2 - 1\) = 1 - 1 = 0
=> f(y) + f(-1) = \(y^2 - 1 + 0\) = \(y^2 - 1\)
So, Answer will be A
Hope it helps!
Watch the following video to MASTER Functions and Custom Characters
To find f(y) we will substitute x with y in \(f(x) = x^2 - 1\)
=> \(f(y) = y^2 - 1\)
Similarly, \(f(-1) = (-1)^2 - 1\) = 1 - 1 = 0
=> f(y) + f(-1) = \(y^2 - 1 + 0\) = \(y^2 - 1\)
So, Answer will be A
Hope it helps!
Watch the following video to MASTER Functions and Custom Characters
