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Homework Help: Limits using Taylor series

  1. Nov 23, 2014 #1
    1. The problem statement, all variables and given/known data

    lim x -> 0 CodeCogsEqn.gif

    2. Relevant equations

    Taylor series for sin cos e and ln ()

    3. The attempt at a solution
    I tried expanding the sine to 3-degree, and everything else 2-degree. I ended up with this:

    Now the problem is that WolframAlpha says it should be -6/25. Now if only that -2 were +2...
  2. jcsd
  3. Nov 23, 2014 #2
    I got the answer! the first 1/2 (expansion from e^3x) is supposed to be 4 1/2 not 1/2, because you get (3x)^2 / 2! not (x)^2/2!
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