Function party

The functions are having a party. Everyone is having fun, except for e to the x off in the corner by himself. The host comes up to him and says, "Enjoy yourself! Integrate!"

e^x responds, "That won't change anything!"

The others continue chatting among themselves. Suddenly, one cries "Watch out! A differentiation operator is coming!"

All immediately hide themselves under the tables, only e^x sits calmly on the chair.

The operator comes in, sees a function and says "Hey, you don't fear me?"

"No, I am e to the x", says the exponential.

"Good for you," replies the operator "I'm d/dy."