1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Limit problem, with mins, I know the answer already and I know it is right. But the l

  1. Sep 20, 2011 #1
    1. The problem statement, all variables and given/known data

    Given the follow LOP P

    I am just going to write down the obj function because that is most important for my question and the constraints aren't

    [tex]w = y_1 - 2y_2 + y_3[/tex]

    I was asked to show that [tex]y = (2t, 3t,t)^t[/tex] is a solution for all [tex]t\geq 0[/tex]

    So w = 2t - 2(3t) +t = 2t - 6t + t = -4t + t = -3t

    Now initally I thought that as [tex]t \to \infty [/tex], [tex]-3t \to -\infty [/tex]

    I checked the key provided by my prof and he took [tex]t \to -\infty [/tex] and [tex]-3t \to \infty [/tex]

    Is it because we always assume w >0?

    The flaw I made is that I never consider [tex]t \to \pm \infty [/tex].




    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Sep 21, 2011 #2

    Mark44

    Staff: Mentor

    Re: Limit problem, with mins, I know the answer already and I know it is right. But t

    In applied problems, the objective function is usually nonnegative, but in more theoretic presentations, I don't see why this needs to be true.
     
  4. Sep 21, 2011 #3
    Re: Limit problem, with mins, I know the answer already and I know it is right. But t

    I asked my prof today and he kinda said the same thing about "yes intuitively that is right, we want obj f > 0". Then he added a bunch of things that confused me even more...

    He stated something like this

    max z = -min(-z)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Limit problem, with mins, I know the answer already and I know it is right. But the l
  1. Ok, simple, i know (Replies: 3)

Loading...