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Initial Value Problem with DSolve

Posted 10 years ago
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I'm trying to use DSolve to solve an initial value problem. I entered:
DSolve[{y'[x] == (x^2 + x y[x] + 4 y[x]^2)/x^2, y[1] == 1}, y[x], x]

That returns the error message:
DSolve::deqn: Equation or list of equations expected instead of True in the first argument {(y^\[Prime])[x]==(x^2+x y[x]+4 y[x]^2)/x^2,True}. >>

How is my syntax incorrect? Why is Mathematica performing logic operations on my equations? Best I can tell, I've matched the code snippet above with examples from the DSolve tutorial.
POSTED BY: D G
I would suspect at some point in your session y[1] was set to be equal to 1, which then makes y[1]==1 evaluate to True, and that is not really an equation. Try
Clear[y];
DSolve[{y'[x] == (x^2 + x y[x] + 4 y[x]^2)/x^2, y[1] == 1}, y[x], x]
POSTED BY: Ilian Gachevski
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