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Fiver
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 Posted: Sat Oct 04, 2008 5:58 am Post subject: Number theory |
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Which of the following expressions can be written as an integer?
I) (82^(1/2)+82^(1/2))^2
II) (82^(1/2))*82
III) (82^(1/2))*(82^(1/2)) |
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Mani_mba
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| Posted: Sat Oct 04, 2008 6:41 am Post subject: |
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| I and III. |
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Morgoth
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| Posted: Sat Oct 04, 2008 9:38 am Post subject: Re: Number theory |
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| Fiver wrote: | Which of the following expressions can be written as an integer?
I) (82^(1/2)+82^(1/2))^2
II) (82^(1/2))*82
III) (82^(1/2))*(82^(1/2)) |
I) (82^(1/2)+82^(1/2))^2 = 2*(sqrt82)^2 = integer
II) (82^(1/2))*82 = 82*sqrt82 = not integer, but it this would have been (sqrt82)^82 it would have been integer.
III) (82^(1/2))*(82^(1/2)) = 82^2/2 = 82 = integer. |
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Fiver
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| Posted: Sun Oct 05, 2008 4:56 am Post subject: Re: Number theory |
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[quote="Morgoth"] | Fiver wrote: |
II) (82^(1/2))*82 = 82*sqrt82 = not integer, but it this would have been (sqrt82)^82 it would have been integer.
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Thats exactly what I thought it was!!!
Thanks buddy. |
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