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B Very basic noob question about integers

  1. Dec 19, 2016 #1
    hi all so this is a very basic question i think and i feel very bad for tumbling here but still i need to clear this, so from childhood i was taught that the negative numbers are less than positive but now when i am studying limits and functions i came across absolute function and it said |-x| = max{-x,x}. alright seems legit but now the book says that max of the two is -x and thats why function came out positive due to double minus sign, so i want to ask how is -x greater than x or i am doing something wrong here? thx for ur help
     
  2. jcsd
  3. Dec 19, 2016 #2

    mfb

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    Staff: Mentor

    If x=-5, then -x=-(-5)=5 is larger than x=-5.

    If x is negative, -x is larger than x, otherwise it is not.
     
  4. Dec 19, 2016 #3
    It's just something that tricks your brain until you think about it for a second.

    Q: Is ## -x ## is a negative number?
    A: Not necessarily.

    You don't know what ##x## is. If ## x = -3 ## then ## -x =-(-3) = 3 ## which is positive.

    I prefer to have the absolute value function written piecewise:

    Absolute-Value-as-Piecewise-Function2.png
     
  5. Dec 19, 2016 #4
    duh! lol that was really a simple one xD but thanks everyone for giving a good explanation :)
     
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