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.
sqrt of x^4+6x^2+9
[#permalink]
Updated on: 25 May 2020, 16:08
Updated on: 25 May 2020, 16:08
3
Bookmarks
00:00
Question Stats:
77% (00:41) correct
22% (00:34) wrong based on 40 sessions
Hide Show timer Statistics
Quantity A |
Quantity B |
\(\sqrt{{x^4 + 6x^2 + 9}}\) |
\(x^2+3\) |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
I used in solving this question choosing number strategy, my question if the \(\sqrt{16}\) will it equal 4 or -4, or only 4? How does the GRE deal with that ?
Source : Greg mat
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: Square root
[#permalink]
25 May 2020, 05:17
25 May 2020, 05:17
1
Asmakan wrote:
Quantity A |
Quantity B |
\(\sqrt{{x^4 + 6x^2 + 9}}\) |
\(x^2+3\) |
I used in solving this question choosing number strategy, my question if the \(\sqrt{16}\) will it equal 4 or -4, or only 4? How does the GRE deal with that ?
Source : Greg mat
16 has two square roots (4 and -4), but the square root notation tells us to take only the POSITIVE square root.
So, \(\sqrt{16}=4\), \(\sqrt{49}=7\), \(\sqrt{100}=10\), etc
Alternatively, if \(x^2 = 16\) (i.e., no square root notation), then either \(x=4\) or \(x=-4\)
Likewise, if \(x^2 = 81\) (i.e., no square root notation), then either \(x=9\) or \(x=-9\)
Does that help?
Cheers,
Brent
Re: Square root
[#permalink]
26 May 2020, 03:08
26 May 2020, 03:08
GreenlightTestPrep wrote:
Asmakan wrote:
Quantity A |
Quantity B |
\(\sqrt{{x^4 + 6x^2 + 9}}\) |
\(x^2+3\) |
I used in solving this question choosing number strategy, my question if the \(\sqrt{16}\) will it equal 4 or -4, or only 4? How does the GRE deal with that?
Source: Greg mat
16 has two square roots (4 and -4), but the square root notation tells us to take only the POSITIVE square root.
So, \(\sqrt{16}=4\), \(\sqrt{49}=7\), \(\sqrt{100}=10\), etc
Alternatively, if \(x^2 = 16\) (i.e., no square root notation), then either \(x=4\) or \(x=-4\)
Likewise, if \(x^2 = 81\) (i.e., no square root notation), then either \(x=9\) or \(x=-9\)
Does that help?
Cheers,
Brent
Yes, but need more clarification, now the \(\sqrt{16}\) , 16 could be a result of 4 and -4 eventhough the notation is not -ve.
