>  Because square root is multivalued.

Even so, I would  consider this to be wrong for 

 a) I don't want my students to think it is true and

 b) the left hand side is two-valued while the right hand 
     side is four-valued and hence they do not agree as
     multi-valued functions. (This objection does not cause
     a problem in your two examples.)

>  Consider sqrt(1-z)*sqrt(1+z)=sqrt(1-z^2) and 
sqrt(z-1)*sqrt(z+1)=sqrt(z^2-1)
>
>  
>

-- 
You received this message because you are subscribed to the Google Groups 
"sage-support" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-support.
For more options, visit https://groups.google.com/groups/opt_out.


Reply via email to