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!

Homework Help: Beginners limit problem

  1. Sep 24, 2009 #1
    1. The problem statement, all variables and given/known data
    Lim sqrt(r)/(r-9)4

    3. The attempt at a solution

    I haven't been able to get started on this one I first tried to factor the bottom but I don't know how to or if that is even the right way to solve this problem. I am thinking maybe I have to multiply the bottom out but that seems a bit tedious.

    is it sufficient to simply test from the left and right in order to get my answer?
    Last edited: Sep 24, 2009
  2. jcsd
  3. Sep 24, 2009 #2


    User Avatar
    Homework Helper

    this limit will be infinite, just by inspection

    the numerator will be 3, whilst the denominator tends to 0

    if you want to show it is unbounded, pick any positive number N, then show you can chose d, such that for |r-9|<d, then F(r) > N

    but in answer to your question it is sufficient to show the limit is the same from the left & right
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook