Unreliable complex calculation in CAS? Bug?

[Dands]

(04-07-2020 11:53 PM)victorvbc Wrote:  It's a numerical precision thing. Both real and imaginary parts are in the order of 10^-14. Since you have to calculate the arc tangent of the ratio of these coordinates to get the angle, for such small values it depends on the numerical error.

So it's a bug or something wrong with my CAS settings?