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Homework Help: Rational eq/inequalities help

  1. Oct 8, 2011 #1
    1. The problem statement, all variables and given/known data

    x^2 +3x +2
    __________ < 0

    2. Relevant equations

    3. The attempt at a solution

    I factored the top to be

    (x+2) (x+1)
    ______________ < 0

    Couldnt cancel anything out, So now i dont know what to do. I missed this lesson in class and i dont really understand wtf im supposed to do. Inequalities usually have 1-3 cases in which we solve for x and create a therefore statement in, however, how am i supposed to solve this?

    In the book it just shows intervals, but is it possible to solve through 3 cases as wel? ie)
    x < -3 , x > 3 (since those are the vertical asymptotes)
  2. jcsd
  3. Oct 8, 2011 #2
  4. Oct 8, 2011 #3


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    Homework Helper

    I use sign charts to solve rational inequalities. See http://www.purplemath.com/modules/ineqsolv3.htm" [Broken] for an example.

    P.S. Why do you continue to bump your thread before waiting 24 hours? It's against the rules, so I've reported you to the mods.
    Last edited by a moderator: May 5, 2017
  5. Oct 8, 2011 #4
    Cuz i dun got 24 hours to wait for a small response. nt tho kid gl
  6. Oct 8, 2011 #5


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    Homework Helper
    Education Advisor
    Gold Member

    The critical values of x of {+3, -3} at which the rational expression is undefined, and the critical values of x of {-2, -1} at which the rational expression is zero, contain the the values which break the Real Numbers into intervals which you can check.

    You then can check any value within EACH of the intervals of the Real Numbers to determine if the value makes the inequality true or false. The intervals to check are obviously (-∞, -3), (-3, -2), (-2, -1), (-1, +3), and {+3, ∞).
  7. Oct 8, 2011 #6


    Staff: Mentor

    Report noted, and acted on.
  8. Oct 8, 2011 #7


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    Staff: Mentor

    Knock off the childish text speak and type in normal English.
  9. Oct 8, 2011 #8


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    Staff: Mentor

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