Is x negative

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Is x negative

by jsl » Thu Sep 25, 2008 3:53 am
Is x negative?

1) (n^3)(1-(x^2)) < 0
2) (x^2)-1 < 0

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by 4meonly » Thu Sep 25, 2008 4:12 am
If I am not missing something

1) (n^3)(1-(x^2)) < 0
if n>0
(1-(x^2)) < 0
x^2>1
x can be positive or negative

or
n<0
(1-(x^2))>0
x^2<1
-1<x<1
x can be positive or negative
INSUFF

2) (x^2)-1 < 0
x^2<1
-1<x<1
x can be positive or negative
INSUFF

(1) and (2)
x^2<1
-1<x<1
x can be positive or negative
INSUFF

Answer E

OA please

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Re: Is x negative

by jackcrystal » Thu Sep 25, 2008 6:47 pm

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by jsl » Fri Sep 26, 2008 12:24 am
Can someone explain in more detail pls?

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by kuroneko1313 » Fri Sep 26, 2008 11:31 am
I got E using the same method 4meonly did.
OA please?

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by jsl » Fri Sep 26, 2008 1:10 pm
E is incorrect.... can anyone else explain the correct answer?

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by bluementor » Fri Sep 26, 2008 3:08 pm
Is x negative?

1) (n^3)(1-(x^2)) < 0
2) (x^2)-1 < 0
Are you sure statement 1 is typed out correctly? Should it not be x^3 instead of n^3?

I remember seeing this problem somewhere...OG11 perhaps?

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