Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Find the limit of this function

  1. May 6, 2008 #1
    Hello there

    Find the lim of this function using Algebra alone and without using
    Newton Method or L'Hapital Rule, only Algebraic manipulation is allowed.

    I have previously posted this lim but no one did solve it algebriaclly, I solved it using
    Algebra and uploaded the solution.

    Lim [tex]\frac{^3\sqrt{x}- 4}{\sqrt{x}- 8}[/tex]
    X ---> 64

    The solution
    [​IMG]
     
    Last edited: May 6, 2008
  2. jcsd
  3. May 6, 2008 #2
    Thanks for the update, although I must have missed the original post. It is quite obvious to me that you would want to factor using the difference of two squares/cubes rule as you have 4 (a perfect square) and 8 (a perfect cube). The only thing that might make one hesitate is that instead of using x^2 and x^3 for the numerator and denominator respectively they use x^(1/3) and x(1/2).
     
  4. May 6, 2008 #3

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    That's impressive! Of course, using L'Hopital's rule (which, I notice, you are not allowed to do) would make it fairly simple.
     
    Last edited: May 6, 2008
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?