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If n is an integer and x^n - x^-n = 0, what is the value of

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If n is an integer and x^n - x^-n = 0, what is the value of [#permalink] New post 21 May 2008, 07:09
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If n is an integer and x^n - x^-n = 0, what is the value of x?

1) x is an integer
2) x <> 0 [x is not equal to 0]
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Re: DS - Set 29 [#permalink] New post 21 May 2008, 09:58
i get E..

x can be 0, -1, 1

1) says x is an integer ok..but it can be 0, -1 or 1
2) says x is not 0..it can be 1, or -1

we need to know N..if N is even..yes.. if odd yes too..
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Re: DS - Set 29 [#permalink] New post 22 May 2008, 05:00
Ans is E

x^n -x^-n = 0 will imply either x = 1 or n=0

st1: X could take any value when n=0 so insuffi
st2: X can never be 0 and doesnot give an exact ans so insuffi

So E
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Re: DS - Set 29 [#permalink] New post 22 May 2008, 16:14
I simplyfied given equation as following

x^2n-1=0

x^2n=1

for this to be true , we must know if x =1/-1 and/or n=0/even ...none of this information given in 2 condition so answer E .
Re: DS - Set 29   [#permalink] 22 May 2008, 16:14
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If n is an integer and x^n - x^-n = 0, what is the value of

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