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jf
11/13/12 12:45pm

In Response To 'Re: Re: a question about substitution'
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Both solutions from Solve work in the equation you asked Solve to solve for.

To select the preferred solution, you need to describe it in a way that Select or Cases can use.

The difference in the internal structure of the two solutions is that the first is multiplied by -1. With Cases, we can describe a pattern that is -1 times something else.

In[8]:= Cases[x /. {{x->-(Sqrt[-\[CapitalDelta]+\[Omega]]/(Sqrt[2] Sqrt[\[Omega]]))},{x->Sqrt[-\[CapitalDelta]+\[Omega]]/(Sqrt[2] Sqrt[\[Omega]])}}, - _ ]

Out[8]= {-(Sqrt[-\[CapitalDelta]+\[Omega]]/(Sqrt[2] Sqrt[\[Omega]]))}

See the attached notebook.


Attachment: 122523question.nb, URL: ,

Subject (listing for 'a question about substitution')
Author Date Posted
a question about substitution a question a... 11/11/12 00:30am
Re: a question about substitution jf 11/12/12 1:02pm
Re: Re: a question about substitution reply 11/12/12 8:09pm
Re: Re: Re: a question about substitution jf 11/13/12 12:45pm
Re: Re: Re: Re: a question about substitution reply 11/13/12 8:09pm
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