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Homework Help: Calculus - Describing a Set

  1. May 8, 2014 #1
    1. The problem statement, all variables and given/known data

    Describe the set {x:|x2-5|<4}


    2. Relevant equations



    3. The attempt at a solution

    I know this is simple stuff but I'm confused as to what way I'm supposed to answer this.

    My current answer is:

    |x2-5|<4
    -4<x2-5<4
    -4+5<x2<4+5
    1<x2<9
    1<x<3

    Is that all the question asks for? Do I need to say anything else?
     
  2. jcsd
  3. May 8, 2014 #2

    HallsofIvy

    User Avatar
    Science Advisor

    If [itex]1< x^2< 9[/itex] then either [itex]1< x< 3[/itex] or [itex]1< -x< 3[/itex] so the solution set is two intervals.
     
  4. May 8, 2014 #3
    Ok thanks for the help HallsofIvy
     
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