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: Yay, more limits!

  1. Oct 6, 2004 #1
    I've can't seem to get this:

    [tex]\lim_{\substack{x\rightarrow 1}} \frac {\sqrt{x} -
    x^2} {1 - \sqrt{x}} [/tex]

    I know it equals 3... I got that from the using numbers close to 1 method and from the dervative of the top over the derivative of the bottom method... trouble is, I don't think that's how he wants us to find the answer because we haven't learned the derivative method yet. :yuck: any help would be awesome.
     
  2. jcsd
  3. Oct 6, 2004 #2

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Set:
    [tex]a=\sqrt{x}[/tex]
    Then:
    [tex]\frac{\sqrt{x}-x^{2}}{1-\sqrt{x}}=a\frac{1-a^{3}}{1-a}[/tex]
    Does that help?
     
  4. Oct 6, 2004 #3
    YES! Oh sweet, thanks a lot!
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook