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!

Finding Delta

  1. Oct 17, 2007 #1
    1. The problem statement, all variables and given/known data

    Find a delta such that |f(x)-l|< epsilon for all x satisfying 0<|x-a|< delta

    f(x)=(x^4)+(1/x); a=1; l=2

    2. Relevant equations

    Lemma Theorem

    3. The attempt at a solution

    0<|x-1|<delta; |(x^4)+(1/x)-2|<epsilon

    |x^4-1|<epsilon/2 and |(1/x)-1|<epsilon/2

    Then I applied third item of the Lemma which is

    if y0 not equal to 0;


    then y not equal to 0 and;


    Then I concluded that the |(1/x)-1|<epsilon/2 part of the solution as;


    However, I could not find any approach for the |x^4-1|<epsilon/2

    Which method shall I apply here?

    Any helps will be appreciated.
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted