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: Brief, basic - lim question

  1. Oct 30, 2007 #1
    Brief, basic -- lim question...

    So, i know this is too basic, but can anyone tell me what the lim of ln(x) is as x approaches
    -infinity
    -neg infinity
    -zero (from left and right)

    --> I know I am supposed to know these, but I think I might be confusing them...

    Thank you!
     
  2. jcsd
  3. Oct 30, 2007 #2
    You can do this analytically, just by visualizing the graph of the function.
    -As x increases, the natural log of x also increases without bound.
    -Are negative numbers part of your domain?
    -What happens to values of ln(x) as x approaces 0? Just look at a graph of the parent function.
     
  4. Oct 30, 2007 #3
    I wouldn't call that analytic. I would think of ln(x) as the inverse of exp(x) and exp(x) has derivative strictly greater than 1 for all x>0.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook