Student Support Forum: 'a question about substitution' topicStudent Support Forum > General > "a question about substitution"

 < Previous Comment | Next Comment > Help | Reply To Comment | Reply To Topic
 Author Comment/Response jf 11/13/12 12:45pm In Response To 'Re: Re: a question about substitution'---------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
 < Previous Comment | Next Comment > Help | Reply To Comment | Reply To Topic