Professor Phil O’Mathy, lunching with his colleague Mal Honnet, was bemoaning the state of mathematics education. “Here we are, in one of the great institutions of learning in the world, and yet I doubt one in a hundred could even integrate xe^x!” Furrowing his massive brow, O’Mathy trudged off to the restroom.
No sooner was O’Mathy out of sight than Honnet called the waitress to their table. “When my friend comes back, he’s going to ask you a question. I want you to answer ‘X minus 1 times e to the x’. Got that? Say it.”
“X minus 1 times e to the x. But…”
“No, Don’t try to understand it. Just say it right, and there’ll be a nice tip in it for you. Now scoot.”
When O’Mathy returned, Honnet told him “You know, I think you’re much too pessimistic. I’ll bet that even our waitress can integrate xe^x. In fact, I’ll put twenty bucks on it. Miss, can you come here for a moment? Go ahead, ask her.”
A bit embarrassed, O’Mathy explained that they were mathematics professors curious about students’ levels of mathematical knowledge. “For instance, miss, how would you answer the question ‘What is the integral of xe^x?'”
Dutifully, she recited “X minus 1 times e to the x”. O’Mathy’s face lit up as he gladly made good his losses. Meanwhile, the waitress stalked off, muttering to herself “Plus a constant!”