Results 1 to 4 of 4

Math Help - Help with some inequalities

  1. #1
    Newbie
    Joined
    Apr 2009
    Posts
    5

    Help with some inequalities

    if theres one thing i really cant do its inequalities. can you guys help me out with some problems which all need to be shown in interval notation,

    thanks

    1) 2x squared+5x-3<0

    2) x squared + 6x +9>0
    - (that minus is below the greater than sign)


    3) x squared - 49 < 0
    -(same with this one to)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,956
    Thanks
    1780
    Awards
    1
    Quote Originally Posted by Ryan7123 View Post
    if theres one thing i really cant do its inequalities. can you guys help me out with some problems which all need to be shown in interval notation,
    You must post some actual problems to get any help.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2009
    Posts
    5
    just did sorry lol i guess i forgot to
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Mar 2007
    Posts
    1,240

    Talking

    To learn, in general, how to solve quadratic inequalities, try some online lessons.

    Long story short: Find the zeroes (which are where the graph crosses the x-axis). These zeroes will divide the number line into intervals. Once you've found these intervals, consider the graph.

    For right-side-up parabolas (that is, for positive quadratics), the graph is below the x-axis (so the quadratic is negative) between the zeroes, and above the x-axis "on the ends" (so the quadratic is positive).

    For upside-down parabolas (that is, for negative quadratics), the graph goes the other way 'round.

    Using the zeroes and what you know about the graphs, pick the appropriate solution intervals.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. inequalities
    Posted in the Algebra Forum
    Replies: 7
    Last Post: August 20th 2011, 05:56 AM
  2. inequalities
    Posted in the Algebra Forum
    Replies: 0
    Last Post: March 20th 2011, 03:42 AM
  3. Inequalities
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: July 1st 2009, 05:35 AM
  4. Inequalities
    Posted in the Algebra Forum
    Replies: 4
    Last Post: June 15th 2009, 12:26 PM
  5. inequalities
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: October 14th 2008, 10:57 PM

Search Tags


/mathhelpforum @mathhelpforum