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# Quant doubt

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Current Student
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27 Aug 2013, 18:17
An extract from GMAT club tests:
Must know for the GMAT: if x is a positive integer then root(x) is either a positive integer or an irrational number. (It cannot be some reduced fraction e.g. 73 or 12).

can't root(x) be negative?
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27 Aug 2013, 18:26
another instance : First of all notice that since x is a positive number then root(x)>0.
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27 Aug 2013, 21:34
nksbits wrote:
another instance : First of all notice that since x is a positive number then root(x)>0.

By definition (as far as GMAT is concerned), $$\sqrt{x}$$ is positive only.

$$\sqrt{4} = 2$$
It is not +2 or -2.

In case you have $$x^2 = 4$$, x can take two values, 2 or -2.
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28 Aug 2013, 10:01
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Re: Quant doubt   [#permalink] 28 Aug 2013, 10:01
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