Math Joke

[TOP]

คลายเครียดหลังสอบเสร็จด้วยขำขันกันหน่อย(แปลเอาเองนะ)

Three employees of NOSC (an engineer, a physicist and a mathematician) are
staying in a hotel while attending a technical seminar. The engineer wakes
up and smells smoke. He goes out into the hallway and sees a fire, so he
fills a trashcan from his room with water and douses the fire. He goes back
to bed. Later, the physicist wakes up and smells smoke. He opens his door
and sees a fire in the hallway. He walks down the hall to a fire hose and
after calculating the flame velocity, distance, water pressure, trajectory,
etc. extinguishes the fire with the minimum amount of water and energy
needed. Later, the mathematician wakes up and smells smoke. He goes to the
hall, sees the fire and then the fire hose. He thinks for a moment and then
exclaims, "Ah, a solution exists!" and then goes back to bed

[TOP]

There was a mad scientist ( a mad ...social... scientist ) who kidnapped
three colleagues, an engineer, a physicist, and a mathematician, and locked
each of them in seperate cells with plenty of canned food and water but no
can opener.

A month later, returning, the mad scientist went to the engineer's cell and
found it long empty. The engineer had constructed a can opener from pocket
trash, used aluminum shavings and dried sugar to make an explosive, and escaped.

The physicist had worked out the angle necessary to knock the lids off the tin
cans by throwing them against the wall. She was developing a good pitching arm and a new quantum theory.

The mathematician had stacked the unopened cans into a surprising solution to
the kissing problem; his dessicated corpse was propped calmly against a wall,
and this was inscribed on the floor in blood:

Theorem: If I can't open these cans, I'll die.

Proof: assume the opposite...

[TOP]

There were two men trying to decide what to do for a living. They went to
see a counselor, and he decided that they had good problem solving skills.

He tried a test to narrow the area of specialty. He put each man in a room
with a stove, a table, and a pot of water on the table. He said "Boil the
water". Both men moved the pot from the table to the stove and turned on the
burner to boil the water. Next, he put them into a room with a stove, a table,
and a pot of water on the floor. Again, he said "Boil the water". The first
man put the pot on the stove and turned on the burner. The counselor told him
to be an Engineer, because he could solve each problem individually. The
second man moved the pot from the floor to the table, and then moved the
pot from the table to the stove and turned on the burner. The counselor
told him to be a mathematician because he reduced the problem to a previously
solved problem.

[TOP]

Several students were asked the following problem:

Prove that all odd integers are prime.

Well, the first student to try to do this was a math student. Hey
says "hmmm... Well, 1 is prime, 3 is prime, 5 is prime, and by
induction, we have that all the odd integers are prime."

Of course, there are some jeers from some of his friends. The
physics student then said, "I'm not sure of the validity of your proof,
but I think I'll try to prove it by experiment." He continues, "Well, 1
is prime, 3 is prime, 5 is prime, 7 is prime, 9 is ... uh, 9 is an
experimental error, 11 is prime, 13 is prime... Well, it seems that
you're right."

The third student to try it was the engineering student, who
responded, "Well, actually, I'm not sure of your answer either. Let's
see... 1 is prime, 3 is prime, 5 is prime, 7 is prime, 9 is ..., 9 is
..., well if you approximate, 9 is prime, 11 is prime, 13 is prime...
Well, it does seem right."

[Hell]

55555 ขำอันแรกที่สุดเลยแฮะ เหมือนผมเลย
เวลาคิดออกแล้วก็ถือว่าทำได้แล้ว ไม่ยอมทำต่อแล้ว

แล้วส่วนใหญ่ทำไมชอบให้นักคณิตศาสตร์ดูโง่กว่าคนอื่นทุกทีสินะ แปลก

[TOP]

น่าจะเป็นเพราะ เขาคิดว่าเราคิดไม่เหมือนคนอื่นมั๊ง

The Dictionary: what mathematics professors say and what they mean by it

The following is a guide to terms which are commonly used but rarely defined. In the search for proper definitions for these terms we found no authoritative, nor even recognized, source. Thus, we followed the advice of mathematicians handed down from time immortal: "Wing 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.
OBVIOUSLY: I hope you weren't sleeping when we discussed this earlier, because I refuse to repeat it.
RECALL: I shouldn't have to tell you this, but for those of you who erase your memory tapes after every test...
WLOG (Without Loss Of Generality): I'm not about to do all the possible cases, so I'll do one and let you figure out the rest.
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.
SKETCH OF A PROOF: I couldn't verify all the details, so I'll break it down into the parts I couldn't prove
Hint: The hardest of several possible ways to do a proof.
Brute force: Four special cases, three counting arguments and two long inductions.
SOFT PROOF: One third less filling (of the page) than your regular proof, but it requires two extra years of course work just to understand the terms.
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.
CANONICAL FORM: 4 out of 5 mathematicians surveyed recommended this as the final form for their students who choose to finish
TFAE (The Following Are Equivalent): If I say this it means that, and if I say that it means the other thing, and if I say the other thing...
BY A PREVIOUS THEOREM: I don't remember how it goes (come to think of it I'm not really sure we did this at all), but if I stated it right (or at all), then the rest of this follows
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.
LET'S TALK THROUGH IT: I don't want to write it on the board lest I make a mistake.
Proceed formally: Manipulate symbols by the rules without any hint of their true meaning.
QUANTIFY: I can't find anything wrong with your proof except that it won't work if x is a moon of Jupiter (Popular in applied math courses).
Proof omitted: Trust me, It's true

[TOP]

The Evolution of Math Teaching

1960s: A peasant sells a bag of potatoes for \$10. His costs amount to 4/5 of his selling price. What is his profit?
1970s: A farmer sells a bag of potatoes for \$10. His costs amount to 4/5 of his selling price, that is, \$8. What is his profit?
1970s (new math): A farmer exchanges a set P of potatoes with set M of money. The cardinality of the set M is equal to 10, and each element of M is worth \$1. Draw ten big dots representing the elements of M. The set C of production costs is composed of two big dots less than the set M. Represent C as a subset of M and give the answer to the question: What is the cardinality of the set of profits?
1980s: A farmer sells a bag of potatoes for \$10. His production costs are \$8, and his profit is \$2. Underline the word "potatoes" and discuss with your classmates.
1990s: A farmer sells a bag of potatoes for \$10. His or her production costs are 0.80 of his or her revenue. On your calculator, graph revenue vs. costs. Run the POTATO program to determine the profit. Discuss the result with students in your group. Write a brief essay that analyzes this example in the real world of economics.

[TOP]

An insane mathematician gets on a bus and starts threatening everybody: "I'll integrate you! I'll differentiate you!!!" Everybody gets scared and runs away. Only one lady stays. The guy comes up to her and says: "Aren't you scared, I'll integrate you, I'll differentiate you!!!" The lady calmly answers: "No, I am not scared, I am e^x ."

[alpha]

55555555 อันสุดท้ายนี่ ปญอ. (ปัญญา...) อย่างแรง
คิดได้ไงเนี่ย
เอ้อแล้ว e^x เนี่ย จับ diff และ Integrate ไม่ไ่ด้รึไง
ถ้าได้ ทำยังไงล่ะพี่ เด็กม.ปลายอยากหาไว้ประดับความรู้อันน้อยนิดมั่ง

integrate e^x dx = e^x
d e^x /dx = e^x
เพราะฉะนั้น ป้าเค้าเลยไม่กลัวยังไงละครับ

หาพิสูจน์ได้ตามหนังสือเรียนครับ

[alpha]

งั้นแสดงว่า d e^x/dx = 1 ใช่มั้ย

[mathcenter]

ไม่ใช่น้อง ก็อย่างที่เขาว่าไง
d e^x /dx = e^x
ไหนว่าอ่านแคลมาแล้วไง

[alpha]

เด็กม.ปลายก็อ่านของม.ปลายสิ ไม่ได้ว่างขนาดไปอ่านแคลชั้นสูงเกินม.ปลายมากๆ หรอก

[TOP]

We're all familiar with the "proof by contradiction" or "proof by induction", but what about these less frequently used but equally effective proofs? Watch for them soon in a lecture near you.

Proof by convection: Lots of hot air and hand waving.

Proof by reduction: At each step, ignore some detail of the original problem. Continue the reduction process until the original problem has been reduced to something trivial, at which point, the proof is complete.

Proof by obfuscation: Generously apply Greek letters, sequences, series, partial deriva-tives, complex numbers, p, and e. Distance your solution from the original problem as much as possible. Once the audience looks sufficiently perplexed, cancel everything, write `= 0, Q.E.D.', and smile confidently.

Proof by trepidation: Write down something which is obviously wrong, and then loudly and angrily defy anyone to prove otherwise.

Proof by delegation: `This proof is left as an exercise.'

Proof by truncation: Cleverly leave your proof until the end of class. When the class time is up and you have not yet finished the proof announce, `We'll continue this proof next class' and then promptly forget about it.

Proof by intoxication: Every time you write an equal sign, take a shot of Jack Daniels. By the time you're done the proof, it makes sense to you even if nobody else gets it.

Proof by prediction: Write down what you want to prove, then predict that one day it will be proven. Whip out some tarot cards and support your claim.

Proof by post-hypnotic suggestion: Begin proof by `You are growing verrrry sleepy . . . '

Proof by condescension: Do lots of things "by inspection", use the phrase `it is blatantly obvious that' and scoff at any questions that arise.

Proof by intervention: Somewhere in the middle of your proof a miracle occurs.

Proof by religion: Describe your proof, tell your students that they have to take it on faith, and instruct them to go home and pray to the all powerful Lambda that they, mere mortals, may be granted the insight to comprehend even a smidgen of this wisdom of the ages.

Proof by bovine excretion: Reference Spivak to support the part of your proof you have absolutely no idea how to do yourself. Use exact page numbers.

ปล. ในที่สุดอินเตอร์เน็ตก็ใช้ได้ซะที ตัดขาดจากที่นี่ซะนาน

[warut]

Two mathematicians, Joe and Richard , were having dinner in a
restaurant. They were arguing about the average
mathematical knowledge of the American public. Richard claimed that this
average was woefully inadequate while Joe
maintained that it was surpassingly high.

"I'll tell you what, "said Richard, "when I get back from the bathroom
we'll ask our waitress a simple calculus question. If
she gets it right, I'll pick up dinner. If not, you do, okay?" they agreed,
but once he'd left Joe called the waitress over.

"When my friend comes back, " he told her, " he's going to ask you a
question; you should respond "one third x cubed'
no matter what the question is; got that? There's twenty bucks in it for
you." She happily agreed to the gag.

Richard returned from the men's room and called the waitress over. "The
food was wonderful," he stated, "incidentally, do you know what the
integral of x squared is?"

The waitress looked startled, then pensive, almost pained. She looked
around the room, at her feet , made gurgling
noises, (Joe was starting to sweat) and finally said, "Umm, one third x
cubed?"

Joe beamed in relief as an astonished Richard paid the check and a clearly
irritated waitress muttered under her
breath, "... plus a constant."