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: Limit of ln as x goes to infinity

  1. Mar 7, 2012 #1
    1. The problem statement, all variables and given/known data
    lim (lnx)^2/x

    2. Relevant equations


    3. The attempt at a solution

    =5lnx/x * (1/lnx)/(1/lnx)


    How do I calculate x/lnx?
  2. jcsd
  3. Mar 7, 2012 #2


    User Avatar
    Homework Helper

    I do not follow you. What have you done?

  4. Mar 7, 2012 #3


    Staff: Mentor

    Where did the 5 come from? In fact, where did any of this come from? What you have makes zero sense to me.

    Also, since you haven't taken the limit yet, you should not get rid of the "lim" symbol.
    This is a problem that is suited to L'Hopital's Rule. Have you covered it yet?
  5. Mar 8, 2012 #4

    what you typed is equivalent to:

    [tex]\displaystyle \lim_{x\to \infty}\dfrac{[ln(x)]^2}{x}[/tex]

    Did you intend

    [tex]\displaystyle \lim_{x\to \infty}[ln(x)]^{\frac{2}{x}} \ ?[/tex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook