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!

Homework Help: One more limit

  1. Mar 23, 2008 #1
    1. The problem statement, all variables and given/known data
    lim as x goes to 1 from the right of 2^1/x-1=inf

    2. Relevant equations

    solve using delta-epsilon

    3. The attempt at a solution

    i am not sure how to prove an infinite limit, I have a defn that states, If for epsilon>0 there exists an M>0 such that x>M implies |f(x)-L|< epsilon. My main problem is that I am not sure how to do it, and how to get the power of two out of the way
  2. jcsd
  3. Mar 23, 2008 #2
    take the log
  4. Mar 23, 2008 #3
    is the definition right?
  5. Mar 23, 2008 #4
    did you mean lim x->1+ 2^(1/(1-x)) = 0?
    Last edited: Mar 23, 2008
  6. Mar 23, 2008 #5
    no the problem says it goes to inf
  7. Mar 23, 2008 #6
    Oh it's lim x->1+ 2^(1/(x-1)), which is inf yea

    The correct definition is

    lim x->a+ f(x) = inf if for all M > 0 there is a d > 0 s.t. 0 < |x-1| < d and x > 1 implies |f(x)| > M
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook