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Math Help - nonlinear ODE

  1. #1
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    nonlinear ODE

    I must explicitly solve the following ODE

    rf''(r)+f'(r)+f'(r)^3=0.

    I used partial fractions to obtain the equation

    \ln f'(r)+\frac{1}{f'(r)}-\ln(f'(r)+1)=\ln r+k

    for some constant k. However, I'm not sure this helps. Any hints or direction would be much appreciated. Thanks!
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  2. #2
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    Re: nonlinear ODE

    I am not sure that your equation is correct :
    Attached Thumbnails Attached Thumbnails nonlinear ODE-edo.jpg  
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  3. #3
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    Re: nonlinear ODE

    You're right... I made an algebra mistake when taking partial fractions. Thanks for the catch!
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