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: Limits of a Trigonometric Function

  1. Oct 9, 2005 #1
    Question:

    lim(x->0) for (tanx - sinx) / (sinx)^2

    This is what I got:

    = (sinx-sinxcosx) / (cosx)(sinx)^2
    = (sinx)(1-cosx) / (sinx)(sinx)(cosx)
    = (1 - cosx) / (sinx)(cosx)

    However, I can't figure out what to do from this step, as the limit still equals 0/0 at this stage.
     
  2. jcsd
  3. Oct 9, 2005 #2

    mezarashi

    User Avatar
    Homework Helper

    Why are we posting twice -_-
     
  4. Oct 9, 2005 #3
    More people in this forum....
     
  5. Oct 10, 2005 #4

    lurflurf

    User Avatar
    Homework Helper

  6. Oct 11, 2005 #5

    CarlB

    User Avatar
    Science Advisor
    Homework Helper

    You might see if you can use this handy trig fact:

    [tex] (1 + \cos(x))(1-\cos(x)) = 1-\cos^2(x) = \sin^2(x)[/tex]

    Carl
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook