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Homework Help: Calc 2 problem in em

  1. Feb 5, 2009 #1
    1. The problem statement, all variables and given/known data
    this integral owned me, can anyone tell me what to do to solve it/ how to solve it or a step by step solution. from 0 to h, 1/((h-r)^2+r^2))dr


    2. Relevant equations



    3. The attempt at a solution
    Im thinking partial factions or trig sub....
     
  2. jcsd
  3. Feb 5, 2009 #2

    Mark44

    Staff: Mentor

    Let's look at the denominator.
    (h - r)^2 + r^2 = h^2 - 2hr + r^2 + r^2
    = 2r^2 - 2hr + h^2
    = 2(r^2 - rh) + h^2

    Now, complete the square in the first expression to get
    2(r - A)^2 + B^2 (you'll have to figure out A and B)

    The antiderivative of the expression above is K * arctan(something) + C.

    Enough of a hint?
     
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