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Homework Help: Solve Differential Equation Using Variation of Parameters

  1. Mar 5, 2012 #1
    1. The problem statement, all variables and given/known data

    Solve y''+25y=10sec(5t)

    2. Relevant equations


    3. The attempt at a solution

    I believe I have the correct answer for yp which is:


    When I plug this into the Webwork field, it says it is incorrect. I checked my answer against Wolfram Alpha and they look the same.

    I was hoping someone could look at it and identify if it was actually correct or not. If not, I can go through the steps here and try to work it out.

    Last edited: Mar 5, 2012
  2. jcsd
  3. Mar 5, 2012 #2
    I figured it out. The value within the log should be an absolute value as it came from the integral of the tangent.
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