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From: carlos.felippa%colorado.edu@gtempaccount.com
Newsgroups: comp.soft-sys.math.mathematica
Subject: Re: DSolve test
Date: Tue, 13 May 2014 02:27:13 +0000 (UTC)
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On Sunday, May 11, 2014 10:46:04 PM UTC-6, Sasa B wrote:
> First, all the best to one of the most influential mechanics teacher of our
> 
> time, I'm glad to give this minor help :)
> 
> 
> 
> 
> 
> Bug doesn't seem fixed
> 
> 
> 
> sol = DSolve[{u'[t] == 2*Sqrt[u[t]], u[0] == 0}, u[t], t]; Print[sol];
> 
> 
> 
> returns
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> {{u[t]->t^2}}
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> 
> 
> (Mathematica 9, Intel 4570)
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> 
> 
> 
> 
> Aleksandar Borkovic
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> 
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> 
> On Fri, May 9, 2014 at 8:07 AM, <
> 
> carlos.felippa%colorado.edu@gtempaccount.com> wrote:
> 
> 
> 
> > Hi, could somebody try this in Mathematica 9 to see if the bug is fixed?
> 
> >
> 
> > sol = DSolve[{u'[t] == 2*Sqrt[u[t]], u[0] == 0}, u[t], t]; Print[sol];
> 
> >
> 
> > Thanks.
> 
> >
> 
> >

Thanks to all who replied.  The bug is still there :-(

u=t=0 is a fixed branch point. Two solutions: u=0 and u=t^2.
DSolve only returns the latter.

I can give other examples if interested.