# Revision history [back]

I think you are right about the fact that you found a bug, which is unfortunately not rare when working in the Symbolic Ring :/ Could you report it on the trac server by yourself (ask for help in comment otherwise) ?

A way to get the correct solution, though not satisfactory, is to simplify the expression zi first, to help the solver:

sage: zzi = zi.full_simplify()
sage: zzi
-cos(phi)/(sqrt(2)*sin(phi) + sqrt(2))

sage: solve(zzi == 0, phi)
[phi == 1/2*pi]


I think you are right about the fact that you found This is indeed a bug, which is unfortunately not rare when working in the Symbolic Ring :/ Could you report it on the trac server by yourself (ask for help in comment otherwise) ?

A way to get the correct solution, though not satisfactory, is to simplify the expression zi first, to help the solver:

sage: zzi = zi.full_simplify()
sage: zzi
-cos(phi)/(sqrt(2)*sin(phi) + sqrt(2))

sage: solve(zzi == 0, phi)
[phi == 1/2*pi]