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Homework Help: Basic differential equation question

  1. Dec 16, 2011 #1
    1. The problem statement, all variables and given/known data

    Solve the equation:

    y' = (1-y2)/ (1-x2) , y(0) = 3

    2. Relevant equations

    MSP508919ib28ff5a89i3a600001e42670hc185fa3i.gif , log(x) is natural logarithm

    3. The attempt at a solution

    After solving, my final result was 3 -y+x-3xy =0, but the given answer is 8x2+y2=9.. can someone please kindly check the answer for me? I checked it several times but I still couldn't find anything wrong with my solution..
  2. jcsd
  3. Dec 16, 2011 #2
    Have you checked to see whether your solution satisfies the initial condition or the original ODE?
  4. Dec 16, 2011 #3
  5. Dec 16, 2011 #4
    I tried it too and I got your answer. Then I checked Wolfram Alpha and it confirmed it.
  6. Dec 16, 2011 #5


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    Homework Helper
    Gold Member

    Me too and confirm check if the 'given answer' satisfies the d.e. :wink:

    (Useful habit too).
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