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Re: If x > 0.9, which of the following could be the value of x? A. 0.81
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21 Nov 2022, 02:05
\(\sqrt{x}\) implies the principal square root i.e. the positive square root of x only.
For example:
\(\sqrt{9} = 3\) only.
\(\sqrt{9}\) is not -3.
When the question wants the negative square root, it will be written as \(-\sqrt{9} = -3\).
It might be against what you might have learnt in school but by convention (and certainly as far as GMAT is concerned), \(\sqrt{x}\) implies the positive square root only.
On the same lines, \(\sqrt{x^2} = |x|\) (only the positive value of x)
Therefore, √0.9 is a positive value greater than 0.9
and √0.01 has only one value which is 0.1 so option (E) becomes 1-0.1 = 0.9. It is not greater than 0.9
Answer: B