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Homework Help: Solve Inequalities with answers in Interval notation.

  1. Jan 7, 2010 #1
    Solve Inequalities with answers in Interval notation.



    x^2 + 1 > 4x



    Solve for x, U = Union

    x^2 - 4x + 1 > 0
    x= 3.732050808, 0.2679491924

    Answer x= 3.732050808 U 0.2679491924 ?
     
  2. jcsd
  3. Jan 7, 2010 #2

    HallsofIvy

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    What you have written, the "union" of two numbers, makes no sense at all. You take the union of sets, not numbers. You need intervals not numbers. The numbers you give, which are better written [itex]2+ \sqrt{3}[/tex] and [tex]2- \sqrt{3}[/tex], are where that left side is equal to 0. Then separate the intervals where it is true from the intervals where it is false. Take one value in each interval to see whether it is ">" or "<".
     
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