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December 12th, 2015, 08:47 AM  #1 
Newbie Joined: Feb 2015 From: Brazil Posts: 13 Thanks: 0 Math Focus: Still figuring it out.  About square roots in quadratic equations where bx=0
Why is 16^1/2=4, but when x²=16, then x=+/4?

December 12th, 2015, 09:11 AM  #2 
Senior Member Joined: Apr 2014 From: Europa Posts: 584 Thanks: 177 
$\displaystyle \sqrt{x^2} =x$ $\displaystyle x^2=16\Longleftrightarrow \sqrt{x^2} = \sqrt{16}\Longleftrightarrow x=4 \Longleftrightarrow x= \pm4 $ 
December 12th, 2015, 09:21 AM  #3 
Newbie Joined: Feb 2015 From: Brazil Posts: 13 Thanks: 0 Math Focus: Still figuring it out. 
Oh, now I see, thank you!

December 12th, 2015, 10:20 AM  #4 
Banned Camp Joined: Jun 2014 From: Earth Posts: 945 Thanks: 191  
January 24th, 2016, 01:31 AM  #5 
Newbie Joined: Feb 2015 From: Brazil Posts: 13 Thanks: 0 Math Focus: Still figuring it out. 
Oh, thank you, I did not know!


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bx0, equations, quadratic, roots, square 
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