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Homework Help: Solving limit

  1. Dec 13, 2009 #1
    1. The problem statement, all variables and given/known data

    limit ......(1-cos(2x^2)) / (1-cos(3x^2))

    2. The attempt at a solution
    since the above gave me 0/0, I used l'Hopital method..
    then i got

    (4x)sin(2x^2) / (6x)(sin3x^2)
    which gives me 0/0 again..

    so I kept on using l'Hopital.. but it seemed on going forever

    is there other way to solve this..?
    thank you in advance
  2. jcsd
  3. Dec 13, 2009 #2


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    Science Advisor
    Homework Helper
    Gold Member

    Don't keep using LH rule. Remember you know (at least you should know):

    [tex]\lim_{x\rightarrow 0}\frac {\sin x} x = 1[/tex]

    See if you can figure out how to use that next.
  4. Dec 13, 2009 #3
    Using LH twice doesn't give 0/0.
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