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Number Systems

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by sukhman » Tue Oct 15, 2013 9:01 am
For which of the following values of x is {1-[2-(x^1/2)]^1/2}^1/2 not defined as a real number?
1 2 3 4 5
Last edited by sukhman on Thu Oct 17, 2013 12:01 am, edited 3 times in total.
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Source: — Data Sufficiency |

by [email protected] » Tue Oct 15, 2013 9:07 am
Hi sukhman,

Are those supposed to be exponents? If so, then they should be written as x^(1/2) or (rootX).

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by sukhman » Tue Oct 15, 2013 9:28 am
Yes sorry , they were exponents.
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by rakeshd347 » Tue Oct 15, 2013 3:14 pm
sukhman wrote:For which of the following values of x is {1-[2-(x ^1/2)]^1/2}^1/2 not defined as a real number?
1 2 3 4 5
Well its E or 5

{1-[2-(x ^1/2)]^1/2}^1/2
If you look at it square root of 5 will be more than 2 and then the red part will yield a negative square root which is not the real number. So E is the answer.
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by lunarpower » Wed Oct 16, 2013 2:21 am
I would suggest typing "√" in the question. I don't know about other readers, but I can't make any sense of that expression with all those 1/2's.

If you're on a Mac, you can type "√" by holding down "alt" and pressing the letter V.

If you're on any other computer, you can copy and paste the "√" that I've conveniently put right here in this post.
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