**MATHEMATICIANS ON THE BEACH**

Why mathematicians aren't usually on the beach?

Because they have sine and cosine to get a tan.

**HOW PEOPLE FROM DIFFERENT PROFESSIONS PROVE THAT EVERY ODD INTEGER BIGGER
THAN 0 IS PRIME:**

**Mathematician**: 3 is a prime, 5 is a prime, 7 is a prime, and by induction
- every odd integer higher than 2 is a prime.

**Physicist**: 3 is a prime, 5 is a prime, 7 is a prime, 9 is an experimental
error, 11 is a prime, ...

**Engineer**: 3 is a prime, 5 is a prime, 7 is a prime, 9 is a prime, 11
is a prime, ...

**Programmer**: 3 is a prime, 5 is a prime, 7 is a prime, 7 is a prime, 7
is a prime, ...

**Salesperson**: 3 is a prime, 5 is a prime, 7 is a prime, 9 -- we'll do
for you the best we can, ...

**Computer Software Salesperson**: 3 is prime, 5 is prime, 7 is prime, 9
will be prime in the next release, ...

**Biologist**: 3 is a prime, 5 is a prime, 7 is a prime, 9 -- results have
not arrived yet, ...

**Advertise**r: 3 is a prime, 5 is a prime, 7 is a prime, 11 is a prime,
...

**Lawyer**: 3 is a prime, 5 is a prime, 7 is a prime, 9 -- there is not enough
evidence to prove that it is not a prime, ...

**Accountant**: 3 is prime, 5 is prime, 7 is prime, 9 is prime, deducing
10% tax and 5% other obligations.

**Statistician**: Let's try several randomly chosen numbers -- 17 is a prime,
23 is a prime, 11 is a prime ...

**Professor**: 3 is prime, 5 is prime, 7 is prime, and the rest are left
as an exercise for the student.

**Computational linguist**: 3 is an odd prime, 5 is an odd prime, 7 is an
odd prime, 9 is a very odd prime, ...

**Psychologist**: 3 is a prime, 5 is a prime, 7 is a prime, 9 is a prime
but tries to suppress it, ...

**Theoretical linguist**: 1 is a prime, … (*)

**WHAT IS "PI"?**

**Mathematician**: Pi is the ratio of the circumference of a circle to its
diameter.

**Engineer**: Pi is about 22/7.

**Physicist**: Pi is 3.14159 plus or minus 0.000005

**Computer Programmer**: Pi is 3.141592653589 in double precision.

**Nutritionis**t: You one track math-minded fellows, Pie is a healthy and
delicious dessert!

**TOP ln(e^10) REASONS WHY e IS BETTER THAN pi**

9) e is easier to spell than pi.

8) pi ~= 3.14 while e ~=2.718281828459045.

7) The character for e can be found on a keyboard, but pi sure can't.

6) Everybody fights for their piece of the pie.

5) ln(pi^1) is a really nasty number, but ln(e^1) = 1.

4) e is used in calculus while pi is used in baby geometry.

3) 'e' is the most commonly picked vowel in Wheel of Fortune.

2) e stands for Euler's Number, pi doesn't stand for squat.

1) You don't need to know Greek to be able to use e.

0) You can't confuse e with a food product.

**SCARING DERIVATION**

The functions are sitting in a bar, chatting (how fast they go to zero at infinity
etc.).

Suddenly, one cries "Beware! Derivation is coming!"

All immediately hide themselves under the tables, only the exponential sits
calmly on the chair.

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

"No, I'm e to x", says the exponential self-confidently.

"Well" replies the derivation "but who says I differentiate along
x?"

**SHORTEST JOKE**

What is the shortest mathematicians joke?

Let epsilon be smaller than zero.

**WHY MATHEMATICIANS ARE DIFFERENT**

An astronomer, a physicist and a mathematician (it is said) were holidaying
in Scotland. Glancing from a train window, they observed a black sheep in the
middle of a field.

"How interesting," observed the astronomer, "all scottish sheep
are black!"

To which the physicist responded, "No, no! Some Scottish sheep are black!"

The mathematician gazed heavenward in supplication, and then intoned, "In
Scotland there exists at least one field, containing at least one sheep, at
least one side of which is black."

An engineer, a chemist and a mathematician are staying in three adjoining cabins at an old motel. First the engineer's coffee maker catches fire. He smells the smoke, wakes up, unplugs the coffee maker, throws it out the window, and goes back to sleep. Later that night the chemist smells smoke too. He wakes up and sees that a cigarette butt has set the trash can on fire. He says to himself, "Hmm. How does one put out a fire? One can reduce the temperature of the fuel below the flash point, isolate the burning material from oxygen, or both. This could be accomplished by applying water." So he picks up the trash can, puts it in the shower stall, turns on the water, and, when the fire is out, goes back to sleep. The mathematician, of course, has been watching all this out the window. So later, when he finds that his pipe ashes have set the bedsheet on fire, he is not in the least taken aback. He says: "Aha! A solution exists!" and goes back to sleep.

A mathematician is in Africa trying to capture a lion. When he spots one he proceeds to build a fence around himself and says, "I define this to be outside!"

**THE CHICKEN AGAIN**

Why did the chicken cross the Möbius strip?

To get to the same side.

**WHO WANTS TO DO HOMEWORK?**

Approximately ten excuses for not doing homework:

- I accidentally divided by zero and my paper burst into flames.
- I could only get arbitrarily close to my textbook. I couldn't actually reach it.
- I have the proof, but there isn't room to write it in this margin.
- I was watching the World Series and got tied up trying to prove that it converged.
- I have a solar powered calculator and it was cloudy.
- I locked the paper in my trunk but a four-dimensional dog got in and ate it.

**THE DICTIONARY**

What mathematics professors say and what they mean by it

**Clearly**: I don't want to write down all the "in-between" steps.-
**Trivial**: If I have to show you how to do this, you're in the wrong class. -
**It can easily be shown**: No more than four hours are needed to prove it. -
**Check for yourself**: This is the boring part of the proof, so you can do it on your own time. -
**Hint**: The hardest of several possible ways to do a proof. -
**Brute force**: Four special cases, three counting arguments and two long inductions. -
**Elegant proof**: Requires no previous knowledge of the subject matter and is less than ten lines long. -
**Similarly**: At least one line of the proof of this case is the same as before. **Two line proof**: I'll leave out everything but the conclusion, you can't question 'em if you can't see 'em.-
**Briefly**: I'm running out of time, so I'll just write and talk faster. -
**Proceed formally**: Manipulate symbols by the rules without any hint of their true meaning. -
**Proof omitted**: Trust me, It's true.

**YOU MIGHT BE A MATHEMATICIAN IF...**

- You have tried to prove Fermat's Last Theorem.
- You know ten ways to prove Pythagoras' Theorem.
- Your telephone number is the sum of two prime numbers.
- You have calculated that the World Series actually diverges.
- You are sure that differential equations are a very useful tool.
- You comment to your wife that her straight hair is nice and parallel.
- When you say to a car dealer "I'll take the red car or the blue one" you must add "but not both of them."

Contributed by Eduardo T. Hidal

(*) This item was contributed by John Rosen on Sept. 6, 2017. His justification:
"The point is that generative linguists (the school founded by Noam Chomsky)
are hyper-quick to generalize."

Edited by V.W.Setzer