Hi, I've found some inappropriate behaviour of the solve function. >>> x,y = symbols("x y", real=True, nonnegative=True) >>> solve(y-x**2,x) [-sqrt(y), sqrt(y)]
The only non-negative case where both sqrt(y) and -sqrt(y) should be solutions is where y=0, in which case they are equal and not different after all. It's quite annoying if there should be a single solution of zero! It should really work like positives: >>> x,y = symbols("x y", real=True, positive=True) >>> solve(y-x**2,x) [sqrt(y)] I didn't submit an issue because I was not sure if it was deliberate (perhaps for making floats work properly?). :L -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy?hl=en-US. For more options, visit https://groups.google.com/groups/opt_out.