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!

Without using L'Hopital's rule, how can I calaculate this limit?

  1. Jan 18, 2013 #1
    Without using L'Hopital's rule how can I calculate the limit of this function: (xn-an)/(x-a) when x→a

    I cannot get rid of the indeterminations no matter what. I would like if you could help me out on this.
     
  2. jcsd
  3. Jan 18, 2013 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    Factor x^n-a^n. For example x^2-a^2=(x-a)(x+a). x^3-a^3=(x-a)(x^2+xa+a^2) etc.
     
  4. Jan 18, 2013 #3

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    Is n a positive integer? If so, just factor, as Dick has already suggested. If n is not a positive integer, you more-or-less need to use l'Hosptial's rule, whether you want to or not.
     
  5. Jan 18, 2013 #4
    I figured that out. Took me a while to notice if I factorized x^n-a^n begining with (x-a)(...) the sum of the other factors would add up to n.a^n-1.

    PS: I apologize not having posted my original atempt in solving the problem like the rules require.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Without using L'Hopital's rule, how can I calaculate this limit?
Loading...