Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Triangle inequaility

  1. Feb 17, 2007 #1
    |(x-1)^2-5x+4|=|(x-1)^2 - 3(x-1)| <= |x-1|^2+3|x-1|
    how does that work? i thought triangle inequaility was |x+y| <= |x|+|y|
    plz explain thanks in advance
     
  2. jcsd
  3. Feb 17, 2007 #2

    quasar987

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Well the first equality is false. - 3(x-1) [itex]\neq[/itex]-5x+4. But the inequality is correct. The triangle inequaity says that

    |x±y|[itex]\leq[/itex]|x|+|y|
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook