Jesus and his disciples are gathered for the Last Supper.
The Last Supper is a Seder, basically a big party, so everyone is sitting around, drinking, chatting, hanging out, whatever. Suddenly, Jesus raises his hands and quiets everyone. The disciples look on attentively while Jesus begins, “Why …
… equals ex squared plus two ex minus six.” Everyone sits in silence for a few moments and meditates on this thought. But eventually they go back to eating and drinking and chatting and so on.
But Thomas is really bothered by this. Thomas doesn’t get it at all, and it is really bugging him. So finally, after a few minutes, Thomas tugs on Judas’ sleeve and says, “Judas, I don’t get it — what the heck was that about?” Judas responds, “Oh, Thomas, don’t worry about it — it was just another one of his parabolas.”
(This is an elaborated version of a joke that was submitted by some students at a Catholic school in lieu of a solution to a problem on the Mandelbrot Competition, c. 2005.)