Re: differences in Solve with -1/2 and -0.5

*To*: mathgroup at smc.vnet.net*Subject*: [mg44399] Re: differences in Solve with -1/2 and -0.5*From*: "David W. Cantrell" <DWCantrell at sigmaxi.org>*Date*: Sat, 8 Nov 2003 04:50:44 -0500 (EST)*References*: <boftfo$5ph$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

"Kenneth Levasseur" <Kenneth_Levasseur at uml.edu> wrote: > Can anyone give a good reason why there is a difference in the > following? Preferably one that my students will understand. > > In[1]:= > Solve[D[x E^(-x/2), x] == 0, x] > Out[1]= > {{x -> 2}} > In[2]:= > Solve[D[x E^(-0.5*x), x] == 0, x] > General::dbyz:Division by zero. > Out[2]= > {} Using the current version of Mathematica, I get Out[2]= {{x -> 2.}} just as one would expect. David