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

Need help finding a bound for an equation

  1. Jul 12, 2012 #1
    I'm trying to find a value K>o such that for real a,b,c,d

    (a^2+c^2)x^2+2(ab+cd)xy+(b^2+d^2)y^2 ≤ K(x^2+y^2).

    Any help on this would be greatly appreciated thanks.
     
  2. jcsd
  3. Jul 12, 2012 #2

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Well, play a bit around using the fact that 2xy is always less than the sum of the two variables squared.
     
  4. Jul 12, 2012 #3
    Thank you very much. I would have been stuck for hours.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Need help finding a bound for an equation
Loading...