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: Quick calc limit question

  1. Sep 18, 2005 #1
    can someone help me out with a simple calc question?

    we are asked to find the limit of a function as t approaches zero. the function is:

    (sint/2t)i + (e^2t)j + (t^2/e^t)k

    why is the answer not just j?

    the answer given is 1/2i + j, but I have no idea how that first term came about.

    help!
     
  2. jcsd
  3. Sep 18, 2005 #2

    shmoe

    User Avatar
    Science Advisor
    Homework Helper

    sin(t)/(2t) as t->0 is one of those indeterminate 0/0 forms, it's not 0 as you seemed to hope. You should know the limit of sin(t)/t as t->0, it's a pretty standard one (or you can use l'hopital's rule).
     
  4. Sep 18, 2005 #3
    [tex]\lim_{t{\to}0}\frac{\sin{t}}{t}=1[/tex]

    edit: i can't remember the diravation at the moment
     
    Last edited: Sep 18, 2005
  5. Sep 18, 2005 #4
    thank you

    thank you:) it's been a while...i forgot about l'hopital's rule. thanks again
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook