I want to convey the following mathematical joke about a supposed dialogue between the imaginary unit (i^2=-1) and the (irrational) number π.
I would convey 'Be rational' by 'Sois rationnel' (nevertheless, the imperative sois sounds more formal to my native ears than be).
I have posted a related question about get real.
Conveying "I mean come on let's get real"
I think in the context of this joke 'get real' could be conveyed by 'Sois réel' to keep the joke. What do you think?