1. Limited time only! Sign up for a free 30min personal 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!

How to find local maxima and minimas of undefined functions?

  1. Apr 13, 2012 #1
    I have been going over past papers and i found this question. Find any local maxima or local minima of the functions g(x) = |f(x)| and h(x) = +√f(x) in the interval, −∞ < x < ∞.
    How Would I go about solving this?
  2. jcsd
  3. Apr 13, 2012 #2


    User Avatar
    Science Advisor

    Hey jackgartlqn and welcome to the forums.

    You're going to need information about f(x). You will need some kind of information to start to answer this question in any kind of detail.

    We do know that g(x) >= 0 no matter what which means in terms of a potential global minima it is always going to be >= 0 and if f(x) is >= 0 then we can say the same for h(x) as well.

    Other than this though, you will need some kind of specific information for f(x) or at least for the properties of f(x).
  4. Apr 13, 2012 #3

    But for the fact that it MUST be [itex]f(x)\geq 0\,\,\forall x\in(-\infty,\infty)[/itex] if [itex]h(x)[/itex] is well defined, you can't deduce anything at all if you're not given

    some more information about [itex]f(x)[/itex] ...continuity, derivability,...?

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook