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Homework Help: Variant of inverse tangent derivative

  1. Jun 8, 2012 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution

    I know that 1/(x^2+1) is the derivative of the inverse tangent function, and that is proved by using tany = x, derivative of both sides with secx=(1+tan^2x) and tan^2x = x^2.

    I don't know how to use the proof of the inverse tangent derivative to calculate the integral of 1/(u^2+4). Am I approaching this in an incorrect way?
  2. jcsd
  3. Jun 8, 2012 #2
    Think about how you can turn that 4 into a 1 without changing the value of the whole expression.
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