Involving Absolute Value

Discussion in 'Other Pre-University Math' started by nycmathguy, Jul 12, 2021.

  1. nycmathguy

    nycmathguy

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    Why should the absolute value be included after taking the square root?

    See attachment.

    20210712_160911.jpg
     
    nycmathguy, Jul 12, 2021
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  2. nycmathguy

    MathLover1

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    sqrt of any number has positive and negative solution
    so, sqrt(x^2) is actually -x or +x
    if you have |x| also means x could be -x or +x

    sqrt(9/4) is same as sqrt(9)/sqrt(4)=3/2 or -3/-2 which is again=3/2

    therefore, |x|=3/2
     
    MathLover1, Jul 12, 2021
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  3. nycmathguy

    nycmathguy

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    Are you saying that the proper way to express the answer after taking the square root is to apply an absolute value?

    Sample:

    x^2 = 16

    sqrt{x^2} = sqrt{16}

    | x | = 4

    Also, | x | = 4 means that x = -4 and x = 4.

    Yes?
     
    nycmathguy, Jul 12, 2021
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