Recent content by bilgek33

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    Second order nonlinear differential equation problem

    the last code Thank you saltydog. I will look at it.
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    Second order nonlinear differential equation problem

    Hi saltydog, I tried to do it one more time and I think what happens is the outer graph is the f=1, and the inner graph is the f=0. When you plot the figure, it shows the last one (which is i=10) the first somehow and the first one (i=1) the last. You can try by individually drawing the figures...
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    Second order nonlinear differential equation problem

    hi saltydog, Thnak you for the code. I couldn't manage to plot everything in one figure. How did you do that? Because when I used your code, it plotted all of the graphs separately. I have another question. As far as I understood, you tell me that for a given b value, the higher the 'f' is...
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    Second order nonlinear differential equation problem

    Somebody also told me about using matlab. He said "ode45" can do it, but I don't know MATLAB good enough to do it.
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    Second order nonlinear differential equation problem

    numerical solution It is actually ok for me to obtain a numerical solution close to zero. However, my background in computational stuff is not very good, since I am a theorist. I just tried to do it numerically with some software (Mathematica) but couldn't do it since it says (there is...
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    Second order nonlinear differential equation problem

    Thanks again for your interest, saltydog. You are right there is typo there, but the result is the same. Here is the corrected one: http://www.people.virginia.edu/~bk5w/home_files/ode2.pdf One another thing is f is between [0,1], which means it can be zero as well (when you wrote, you...
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    Second order nonlinear differential equation problem

    I also what I meant by singular initial value problem is the following my initial conditions are z(0)=0 and z'(0)=0 However, when b=0, the differential equation I wrote before, involves division by zero, which creates a problem.
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    Second order nonlinear differential equation problem

    Hi saltydog. Thanks for the welcome. Your solution way when f=1 is correct and it is true that it works when b is not 0. Hence, I also think that the solution is not unique when b=0. I also provided different ways of solving it when f=1. (I attached a pdf file below). Do you know how to...
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    Second order nonlinear differential equation problem

    I need to solve the following second order nonlinear differential equation: z''(b) * [6(1 - f)z(b) + (1+f)b z'(b)] = (15 - 9 f)[z'(b)]^2 + [2(1 - f) z(b) z'(b)] / b + [4 f z'(b)^(5/2)] / b^(1/2) where f is a constant between [0,1]. initial conditions are z(0)=0 and z'(0)=0 I...
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