My dearest wife,

We have been married for nearly thirty years, and I still love you as much as on the day I proposed. You must realize, however, that you are now 54 years old and no longer able to satisfy certain needs I still have. I very much hope that you are not hurt to learn that, while you're reading this, I'm in a hotel room with an 18-year-old freshman girl from my calculus class. I'll be home before midnight.

Your husband, who will never stop loving you.

When the professor returns from the hotel shortly before midnight, he also finds an envelope in the living room. He opens it and reads:

My beloved husband,

You may recall that you, too, are 54 years old and no longer able to satisfy certain needs I still have. I thus hope that you are not hurt to learn that, while you're reading this, I am in a hotel room with the 18-year-old pool boy.

Your loving wife.

P.S. As a mathematician, you are certainly aware of the fact that

"How much for one of your sheep?" he asks the shepherd.

"They aren't for sale", the shepherd replies.

The math biologist ponders for a moment and then says: "I will give you the precise number of sheep in your herd without counting. If I'm right, don't you think that I deserve one of them as a reward?" The shepherd nods.

The math biologist says: "387".

The shepherd is silent for a while and then says: "You're right. I hate to loose any of my sheep, but I promised: One of them is yours. Have your pick!"

The math biologist grabs one of the animals, puts it on his shoulders, and is about to march on, when the shepherd says: "Wait! I will tell you what your profession is, and if I'm right I'll get the animal back."

"That's fair enough." "You must be a mathematical biologist."

The man is stunned. "You're right. But how could you know?"

"That's easy: You gave me the precise number of sheep without counting - and then you picked my dog..."

A man who had just joined the disciples looked very confused and asked Peter: "What, on Earth, does he mean by that?"

Peter replied: "Don't worry - it's just another one of his parabolas."

A: Every function has a Taylor series which converges to the function and breaks off after the linear term.

"She just filed for divorce..."

"I don't believe it! Did you forget about your wedding day?"

"No. Actually, on my way back home from work, I stopped at a flower store and bought a bouquet of red roses for my wife. When I came home, I gave her the roses and said: "I love you." "So, what happened?!" "Well, she took the roses, slapped them around my face, kicked me in the groin, and threw me out of our apartment..."

"What a bitch!"

"No, no... it's all my fault... I should have said: "I love you and only you."

The applied mathematician's solution: We have 2 * 2 = 2 *1/(1-1/2).

The second factor on the right hand side has a geometric series expansion

1/(1-1/2) = 1 + 1/2 +1/4 + 1/8 + ....

Cutting off the series after the second term yields the approximate solution

2 * 2 = 2 *(1 +1/2) = 3.

The pure mathematician's solution: We have 2 * 2 = (-2) *1/(1-3/2).

The second factor on the right hand side has a geometric series expansion

1/(1-3/2) = 1 + 3/2 +9/4 + 27/8 + ...,

which diverges. Hence, the solution to 2 * 2 does not exist.