Another Math “Joke”

Sum 1 to N writes the following:

A math professor is proving some general theorem, and ends up with a result involving [tex]x[/tex]’s and [tex]y[/tex]’s. One student raises his hand and asks, “Can you show us a special case of that theorem?”. In other words, the student wanted a specific application of the theorem. The professor proceeds to erase the [tex]x[/tex]’s and [tex]y[/tex]’s and replace them with [tex]x_0[/tex]’s and [tex]y_0[/tex]’s. The student replies, “Ah! That makes more sense.”

As it is trivially obvious to the most casual observer, the extension of the theorem to [tex]x_1[/tex] and [tex]y_1[/tex] is left as an exercise to the interested reader.

And it will be on the test.