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!

Another Infinite Limit - Quite stuck

  1. May 18, 2010 #1
    1. The problem statement, all variables and given/known data

    [tex] \lim_{t \to \infty} \frac {5t+2}{t^{2}-6t+1} [/tex]

    2. Relevant equations



    3. The attempt at a solution

    Like the title says i am quite stuck, I don't see the first move to make, so if someone could point me in the right direction instead of telling me the answer it would be appreciated.

    I tried to factor the bottom trinomial but it wouldn't help out anyway, and fatoring out a t from the top and either a t or t^{2} from the bottom doesn't seem to get me any where. And the answer is suppose to be 0, according to the book.

    thanks again!
     
  2. jcsd
  3. May 18, 2010 #2
    You can start in a similar way to your last problem and factor out a t from both top and bottom. Look then at what the numerator and denominator tend to when t approaches infinity.
     
  4. May 18, 2010 #3
    ok well if you go at it that way it will be:

    [tex] \lim_{t \to \infty} \frac {t(5+2t^{-1})}{t(t-6+t^{-1})} [/tex]

    [tex] \lim_{t \to \infty} \frac {5+2t^{-1}}{t-6+t^{-1}} [/tex]

    which is saying that when:

    [tex] H= \infty \;\;\;\;\;and\;\;\;\;\; \epsilon=\frac{1}{H} = infinitesimal [/tex]

    it is:

    [tex] \frac {5 + \epsilon}{H-6+\epsilon} [/tex]

    which is basically 5 divided by infinity, I don't see why that that equals 0

    according to my notes an a constant number divided by an infinite number is going to be an infinitesimal number, is that why the limit is 0? because

    [tex] \frac {5}{H} = \epsilon [/tex]

    and epsilon is going to be infinitely close to 0?
     
  5. May 18, 2010 #4

    Mark44

    Staff: Mentor

    The larger H gets, the smaller epsilon gets, so yes, 5/H can be made arbitrarily close to zero.
     
  6. May 18, 2010 #5
    ok thanks for the help again guys
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Another Infinite Limit - Quite stuck
  1. Infinite limits (Replies: 2)

  2. Infinit limit (Replies: 4)

  3. Infinite limits (Replies: 2)

  4. Infinite Limits (Replies: 5)

  5. Infinite limits (Replies: 4)

Loading...