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, please help!

  1. Apr 19, 2008 #1

    I've been given a long limit problem to solve and i got stuck on this part in the question. Could someone please give me hints or suggestions on where to go next?

    Given that [tex]\frac{e^{x}}{x^{n}}[/tex] > e[tex]^{x - n\sqrt{x}}[/tex]

    Find the [tex]lim_{x\rightarrow+\infty}[/tex] [tex]\frac{e^{x}}{x^{n}}[/tex]

    Well i know that [tex]lim_{x\rightarrow\infty}[/tex] e[tex]^{x}[/tex] = [tex]\infty[/tex]

    but i think the question would like us to use the inequality above.

    Any help would be greatly appreciated :)
  2. jcsd
  3. Apr 19, 2008 #2

    Tom Mattson

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I don't see how the inequality helps. Do you know about power series? If so, then can you write down a power series for the function [itex]e^x/x^n[/itex], and take its limit?
  4. Apr 19, 2008 #3
    umm... i haven't learnt power series... Is there another approach i could take??
    i tried l'hospitals rule but my answer didn't help much in this...
  5. Apr 19, 2008 #4


    User Avatar
    Science Advisor
    Homework Helper

    Hi caelestis! :smile:

    Hint: prove that lim (x - n√x) = ∞. :smile:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Limit problem, please help!