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• Hey guys!! Can you help me with this and explain me why?? Thanks!! The solution for: square root of (x^2) = -x I was pretty sure the answer was (inf, 0) but
Message 1 of 2 , Jan 2, 2011
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Hey guys!! Can you help me with this and explain me why?? Thanks!!
The solution for: square root of (x^2) = -x
I was pretty sure the answer was (inf, 0) but www.wolframalpha.com tells me is (inf, 0]
Anyone can tell me why?

[Non-text portions of this message have been removed]
• The only difference between your two answers is that you exclude 0 whereas the website includes (correctly) 0. Since 0^2 = 0 and the square root of 0 is 0, the
Message 1 of 2 , Jan 2, 2011
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The only difference between your two answers is that you exclude 0 whereas the website includes (correctly) 0. Since 0^2 = 0 and the square root of 0 is 0, the left side of the equation works out to 0. The right side is also 0 since -0 = 0. Thus, 0 works. (For what it's worth, I assume you mean to use interval notation so that, for example, (2,8] represents all real numbers strictly greater than 2 and less than or equal to 8, and I assume by "inf" you actually mean negative infinity.)

-----Original Message-----
From: Heriberto Gonzáles <heribertogonzales@...>
To: mathforfun <mathforfun@yahoogroups.com>
Sent: Sun, Jan 2, 2011 3:26 pm
Subject: [MATH for FUN] Need help!! It's easy!!

Hey guys!! Can you help me with this and explain me why?? Thanks!!

The solution for: square root of (x^2) = -x

I was pretty sure the answer was (inf, 0) but www.wolframalpha.com tells me is

(inf, 0]

Anyone can tell me why?

[Non-text portions of this message have been removed]

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