Math Jokes

• Did you hear about the mathematician with constipation ? He had to work it out with a pencil...




• Several scientists were all posed the following question: “What is pi ?”

  The engineer said: “It is approximately 3 and 1/7″

  The physicist said: “It is 3.14159″

  The mathematician thought a bit, and replied “It is equal to pi”.

  A nutritionist: “Pie is a healthy and delicious dessert!”

  Submitted by vicky.

• Old mathematicians never die - they just lose some of their functions.

• I love math - it makes people cry.

• Math problems? Call 1-800-[(10x)(13i)^2]-[sin(xy)/2.362x].

  If parallel lines meet at infinity – infinity must be a very noisy place with all those lines crashing together!

  Zenophobia: the irrational fear of convergent sequences.

  Philosophy is a game with objectives and no rules. Mathematics is a game with rules and no objectives.

  If I had only one day left to live, I would live it in my statistics class: it would seem so much longer.

  Maths Teacher: Now suppose the number of sheep is x…
  Student: Yes sir, but what happens if the number of sheep is not x?

  Submitted by vicky.

• A new government 10 year survey cost $3,000,000,000 revealed that 3/4 of the people in America make up 75% of the population.
  
  According to recent surveys, 51% of the people are in the majority.
  
  Did you know that 87.166253% of all statistics claim a precision of results that is not justified by the method employed?
  
  80% of all statistics quoted to prove a point are made up on the spot.
  
  According to a recent survey, 33 of the people say they participate in surveys.
  
  Q: What do you call a statistician on drugs?
  A: A high flyer.
  
  Q: How many statisticians does it take to change a lightbulb?
  A: 1-3, alpha = .05
  
  There is no truth to the allegation that statisticians are mean. They are just your standard normal deviates.
  
  Q: Did you hear about the statistician who invented a device to measure the weight of trees?
  A: It's referred to as the log scale.
  
  Q: Did you hear about the statistician who took the Dale Carnegie course?
  A: He improved his confidence from .95 to .99.
  
  Q: Why don't statisticians like to model new clothes?
  A: Lack of fit.
  
  Q: Did you hear about the statistician who was thrown in jail?
  A: He now has zero degrees of freedom.
  
  Statisticians must stay away from children's toys because they regress so easily.
  
  The only time a pie chart is appropriate is at a baker's convention.
  
  Never show a bar chart at an AA meeting.
  
  Old statisticians never die, they just undergo a transformation.
  
  Q: How do you tell one bathroom full of statisticians from another?
  A: Check the p-value.
  
  Q: Did you hear about the statistician who made a career change and became an surgeon specializing in ob/gyn?
  A: His specialty was histerectograms.
  
  The most important statistic for car manufacturers is autocorrelation.
  
  Some statisticians don't drink because they are t-test totalers. Others drink the hard stuff as evidenced by the proliferation of box-and-whiskey plots.
  
  Underwater ship builders are concerned with sub-optimization.
  
  The Lipton Company is big on statistics--especially t-tests.
  
  

• Q: Did you hear that joke about the infinite line?A: Don’t worry, It doesn’t have a point!

• Zenophobia: the irrational fear of convergent sequences.

• A guy is flying in a hot air balloon and he's lost.So he lowers himself over a field and shouts to a guy on the ground:"Can you tell me where I am, and which way I'm headed?""Sure! You're at 43 degrees, 12 minutes, 21.2 seconds north; 123 degrees, 8 minutes, 12.8 seconds west. You're at 212 meters above sea level. Right now, you're hovering, but on your way in here you were at a speed of 1.83 meters per second at 1.929 radians""Thanks! By the way, are you a statistician?""I am! But how did you know?""Everything you've told me is completely accurate; you gave me more detail than I needed, and you told me in such a way that it's no use to me at all!""Dang! By the way, are you a principal investigator?""Geeze! How'd you know that?""You don't know where you are, you don't know where you're going. You got where you are by blowing hot air, you start asking questions after you get into trouble, and you're in exactly the same spot you were a few minutes ago, but now, somehow, it's my fault!"

• It is proven that the celebration of birthdays is healthy. Statistics show that those people who celebrate the most birthdays become the oldest. -- S. den Hartog, Ph D. Thesis Universtity of Groningen.
  
  

• Theorem : All numbers are equal to zero.

  Proof: Suppose that a=b. Then
  a = b
  a^2 = ab
  a^2 – b^2 = ab – b^2
  (a + b)(a – b) = b(a – b)
  a + b = b
  a = 0

  Furthermore if a + b = b, and a = b, then b + b = b, and 2b = b, which mean that 2 = 1.

  Submitted by vicky.

• Two statisticians were travelling in an airplane from LA to New York. About an hour into the flight, the pilot announced that they had lost an engine, but don't worry, there are three left.
  
  However, instead of 5 hours it would take 7 hours to get to New York. A little later, he announced that a second engine failed, and they still had two left, but it would take 10 hours to get to New York.
  
  Somewhat later, the pilot again came on the intercom and announced that a third engine had died. Never fear, he announced, because the plane could fly on a single engine.
  
  However, it would now take 18 hours to get to new York. At this point, one statistician turned to the other and said, "Gee, I hope we don't lose that last engine, or we'll be up here forever!"
  
  

• Theorem: 1 = 1/2:
  Proof:
  
  We can re-write the infinite series 1/(1*3) + 1/(3*5) + 1/(5*7) + 1/(7*9)
  +...
  
  as 1/2((1/1 - 1/3) + (1/3 - 1/5) + (1/5 - 1/7) + (1/7 - 1/9) + ... ).
  All terms after 1/1 cancel, so that the sum is 1/2.
  
  We can also re-write the series as (1/1 - 2/3) + (2/3 - 3/5) + (3/5 - 4/7)
  + (4/7 - 5/9) + ...
  
  All terms after 1/1 cancel, so that the sum is 1.
  
  Thus 1/2 = 1.
  
  

• There is no logical foundation of mathematics, and Gödel has proved it!

• Theorem: 1$ = 10 cent
  Proof:
  We know that $1 = 100 cents
  Divide both sides by 100
  $ 1/100 = 100/100 cents
  => $ 1/100 = 1 cent
  Take square root both side
  => squr($1/100) = squr (1 cent)
  => $ 1/10 = 1 cent
  Multiply both side by 10
  => $1 = 10 cent
  
  

• Theorem: 3=4
  Proof:
  
  Suppose:
  a + b = c
  
  This can also be written as:
  4a - 3a + 4b - 3b = 4c - 3c
  
  After reorganizing:
  4a + 4b - 4c = 3a + 3b - 3c
  
  Take the constants out of the brackets:
  4 * (a+b-c) = 3 * (a+b-c)
  
  Remove the same term left and right:
  4 = 3
  
  

• A statistician's wife had twins.He was delighted.He rang the minister who was also delighted. "Bring them to church on Sunday and we'll baptize them," said the minister."No," replied the statistician."Baptize one. We'll keep the other as a control."

• Philosophy is a game with objectives and no rules.

  Mathematics is a game with rules and no objectives.

  Submitted by vijay.

• Theorem: 3=4
  Proof:

  Suppose:
  a + b = c

  This can also be written as:
  4a – 3a + 4b – 3b = 4c – 3c

  After reorganizing:
  4a + 4b – 4c = 3a + 3b – 3c

  Take the constants out of the brackets:
  4 * (a+b-c) = 3 * (a+b-c)

  Remove the same term left and right:
  4 = 3

  Submitted by vicky.

• So Descartes goes into a bar late one night for a beer.At closing time, the bartender makes Last Call and asks him, "Get you another?"Descartes replies, "I think not." And disappears.

• Teacher asks student: What is the half of 8?Student: Miss horizontally or vertically?Teacher: What do mean?Student: Horizontally it is 0 and vertically it is 3.

• Why is 6 afraid of 7? Because 7 ate 9!

• What is the shortest mathematicians joke?Let epsilon be smaller than zero.

• "What happened to your girlfriend, that really cute math student?""She no longer is my girlfriend. I caught her cheating on me.""I don't believe that she cheated on you!""Well, a couple of nights ago I called her on the phone, and she told me that she was in bed wrestling with three unknowns..."

• Q:Why is the number eight afraid of the number seven?A:Because seven ate nine.

• "Students nowadays are so clueless", the math professor complains to a colleague. "Yesterday, a student came to my office hours and wanted to know if General Calculus was a Roman war hero..."

• An engineer and a physicist are in a hot-air balloon. After a few hours they lose track of where they are and descend to get directions. They yell to a jogger, "Hey, can you tell us where we're at?"After a few moments the jogger responds, "You're in a hot-air balloon." The engineer says, "You must be a mathematician." The jogger, shocked, responds, "yeah, how did you know I was a mathematician?""Because, it took you far too long to come up with your answer, it was 100% correct, and it was completely useless."

• What did one math book say to the other math book?"I don't know about you man, but I got a lot of problems!"

• Two statisticians go bird hunting.The first one fires at the bird but overshoots by 5 feet.The second one fires and undershoots the bird by 5 feet.They both give each other a high-five and say "Got it!"

• What happened to the plant in math class? It grew square roots.

• Theorem : All numbers are equal to zero.
  
  Proof: Suppose that a=b. Then
  a = b
  a^2 = ab
  a^2 - b^2 = ab - b^2
  (a + b)(a - b) = b(a - b)
  a + b = b
  a = 0
  
  Furthermore if a + b = b, and a = b, then b + b = b, and 2b = b, which mean that 2 = 1.
  
  

• A boy was teaching a girl arithmetic, he said it was his mission.

  He kissed her once; he kissed her twice and said, “Now that’s addition.”

  In silent satisfaction, she sweetly gave the kisses back and said, “Now that’s subtraction.”

  Then he kissed her, she kissed him, without an explanation.

  And both together smiled and said, “That’s
  multiplication.”

  Then her Dad appeared upon the scene and made a quick decision.

  He kicked that boy three blocks away and said, “That’s long division!”

  Submitted by vicky.

• Q: How many mathematicians does it take to change a lightbulb?A: On average or do you want the whole distribution?

• Q: What does the zero say to the the eight? A: Nice belt!

• It is often cited that there are half as many divorces as marriages in the US, so one concludes that average marriages have a 50% chance of ending by divorce. While I was a graduate student, among my peers there were twice as many divorces as marriages, leading us to conclude that average marriages would end twice...
  
  

• Mathematics is made of 50 percent formulas, 50 percent proofs, and 50 percent imagination.

• Theorem: 1 + 1 = 2
  Proof:
  n(2n - 2) = n(2n - 2)
  n(2n - 2) - n(2n - 2) = 0
  (n - n)(2n - 2) = 0
  2n(n - n) - 2(n - n) = 0
  2n - 2 = 0
  2n = 2
  n + n = 2
  or setting n = 1
  1 + 1 = 2
  
  

• Theorem: 3=4
  Proof:

  Suppose:
  a + b = c

  This can also be written as:
  4a – 3a + 4b – 3b = 4c – 3c

  After reorganizing:
  4a + 4b – 4c = 3a + 3b – 3c

  Take the constants out of the brackets:
  4 * (a+b-c) = 3 * (a+b-c)

  Remove the same term left and right:
  4 = 3
  LOL

  Submitted by vicky.

• A team of engineers were required to measure the height of a flag pole. They only had a measuring tape, and were getting quite frustrated trying to keep the tape along the pole. It kept falling down, etc.A mathematician comes along, finds out their problem, and proceeds to remove the pole from the ground and measure it easily. When he leaves, one engineer says to the other: "Just like a mathematician! We need to know the height, and he gives us the length!"

• Two random variables were talking in a bar. They thought they were being discrete but I heard their chatter continuously.

• Why was the math textbook so sad? He had a lot of problems!

• Theorem: log(-1) = 0
  Proof:
  a. log[(-1)^2] = 2 * log(-1)
  
  On the other hand:
  b. log[(-1)^2] = log(1) = 0
  
  Combining a) and b) gives:
  2* log(-1) = 0
  Divide both sides by 2:
  log(-1) = 0
  
  

• Teacher: Your behaviour reminds me of square root of 2? Student: Why? Teacher: Because its’ completely irrational.

• How I see math word problems:If you have 4 pencils and 7 apples, how many pancakes will fit on the roof?Purple, because aliens don't wear hats.

• A mathematician and his best friend, an engineer, attend a public lecture on geometry in thirteen-dimensional space. "How did you like it?" the mathematician wants to know after the talk."My head's spinning," the engineer confesses. "How can you develop any intuition for thirteen-dimensional space?""Well, it's not even difficult.All I do is visualize the situation in n-dimensional space and then set n = 13."

• The bartender asks: "Would all three of you like some beer?"The first one replies, "I don't know."The second one replies, "I don't know either."The third replies, "Yes."

• A shoeseller meets a mathematician and complains that he does not know what size shoes to buy. "No problem," says the mathematician, "there is a simple equation for that," and he shows him the Gaussian normal distribution. The shoeseller stares some time at het equation and asks, "What is that symbol?" "That is the Greek letter pi." "What is pi?" "That is the ratio between the circumference and the diameter of a circle." Upon this the shoeseller cries out: "What does a circle have to do with shoes?!"
  
  

• An infinite number of mathematicians walk into a bar. The first orders a beer, the second orders half a beer, the third orders a quarter of a beer, and so on.After the seventh order, the bartender pours two beers and says, "You fellas ought to know your limits."

• 1. Ten percent of all car thieves are left-handed
  2. All polar bears are left-handed
  3. If your car is stolen, there's a 10 percent chance it was taken by a Polar bear
  
  1. 39 percent of unemployed men wear spectacles
  2. 80 percent of employed men wear spectacles
  3. Work stuffs up your eyesight
  
  1. All dogs are animals
  2. All cats are animals
  3. Therefore, all dogs are cats
  
  1. A total of 4000 cans are opened around the world every second
  2. Ten babies are conceived around the world every second
  3. Each time you open a can, you stand a 1 in 400 chance of becoming pregnant
  
  

• A mathematician is a blind man in a dark room looking for a black cat which isn't there.

• Q:What is the difference between a mathematician and a philosopher?A: The mathematician only needs paper, pencil, and a trash bin for his work. The philosopher can do without the trash bin.

• Q:What do you get if you add two apples and three apples?A:A high school math problem!

• Analysis:
  1. Differentiate it and put into the refrig. Then integrate it in the refrig.
  2. Redefine the measure on the referigerator (or the elephant).
  3. Apply the Banach-Tarsky theorem.
  
  Number theory:
  1. First factorize, second multiply.
  2. Use induction. You can always squeeze a bit more in.
  
  Algebra:
  1. Step 1. Show that the parts of it can be put into the refrig. Step 2. Show that the refrig. is closed under the addition.
  2. Take the appropriate universal refrigerator and get a surjection from refrigerator to elephant.
  
  Topology:
  1. Have it swallow the refrig. and turn inside out.
  2. Make a refrig. with the Klein bottle.
  3. The elephant is homeomorphic to a smaller elephant.
  4. The elephant is compact, so it can be put into a finite collection of refrigerators. That's usually good enough.
  5. The property of being inside the referigerator is hereditary. So, take the elephant's mother, cremate it, and show that the ashes fit inside the refrigerator.
  6. For those who object to method 3 because it's cruel to animals. Put the elephant's BABY in the refrigerator.
  
  Algebraic topology:
  Replace the interior of the refrigerator by its universal cover, R^3.
  
  Linear algebra:
  1. Put just its basis and span it in the refrig.
  2. Show that 1% of the elephant will fit inside the refrigerator. By linearity, x% will fit for any x.
  
  Affine geometry:
  There is an affine transformation putting the elephant into the refrigerator.
  
  Set theory:
  1. It's very easy! Refrigerator = { elephant } 2) The elephant and the interior of the refrigerator both have cardinality c.
  
  Geometry:
  Declare the following:
  Axiom 1. An elephant can be put into a refrigerator.
  
  Complex analysis:
  Put the refrig. at the origin and the elephant outside the unit circle. Then get the image under the inversion.
  
  Numerical analysis:
  1. Put just its trunk and refer the rest to the error term.
  2. Work it out using the Pentium.
  
  Statistics:
  1. Bright statistician. Put its tail as a sample and say "Done."
  2. Dull statistician. Repeat the experiment pushing the elephant to the refrig.
  3. Our NEW study shows that you CAN'T put the elephant in the refrigerator.
  
  

• 1. They speak only the Greek language.
  
  2. They usually have long threatening names such as Bonferonni, Tchebycheff, Schatzoff, Hotelling, and Godambe. Where are the statisticians with names such as Smith, Brown, or Johnson?
  
  3. They are fond of all snakes and typically own as a pet a large South American snake called an ANOCOVA.
  
  4. For perverse reasons, rather than view a matrix right side up they prefer to invert it.
  
  5. Rather than moonlighting by holding Amway parties they earn a few extra bucks by holding pocket-protector parties.
  
  6. They are frequently seen in their back yards on clear nights gazing through powerful amateur telescopes looking for distant star constellations called ANOVA's.
  
  7. They are 99% confident that sleep can not be induced in an introductory statistics class by lecturing on z-scores.
  
  8. Their idea of a scenic and exotic trip is traveling three standard deviations above the mean in a normal distribution.
  
  9. They manifest many psychological disorders because as young statisticians many of their statistical hypotheses were rejected.
  
  10. They express a deap-seated fear that society will someday construct tests that will enable everyone to make the same score. Without variation or individual differences the field of statistics has no real function and a statistician becomes a penniless ward of the state.
  
  

• An astronomer, a physicist and a mathematician are on a train in Scotland. The astronomer looks out of the window, sees a black sheep standing in a field, and remarks, "How odd. Scottish sheep are black.""No, no, no!" says the physicist. "Only some Scottish sheep are black."The mathematician rolls his eyes at his companions' muddled thinking and says, "In Scotland, there is at least one field, containing at least one sheep, at least one side of which appears black from here."

• Dear Maths,Please grow up now and solve you problems yourself.

• Q: How do mathematicians induce good behavior in their children? A: "If I've told you n times, I've told you n+1 times..."

• Q: Do you already know the latest stats joke? A: Probably...

• A logician's wife is having a baby. The doctor immediately hands the newborn to the dad.His wife asks impatiently: "So, is it a boy or a girl" ?The logician replies: "yes".

• There was this statistics student who, when driving his car, would always accelerate hard before coming to any junction, whizz straight over it , then slow down again once he'd got over it. One day, he took a passenger, who was understandably unnerved by his driving style, and asked him why he went so fast over junctions. The statistics student replied, "Well, statistically speaking, you are far more likely to have an accident at a junction, so I just make sure that I spend less time there."
  
  

• Three professors (a physicist, a chemist, and a statistician) are called in to see their dean. Just as they arrive the dean is called out of his office, leaving the three professors there. The professors see with alarm that there is a fire in the wastebasket.The physicist says, "I know what to do! We must cool down the materials until their temperature is lower than the ignition temperature and then the fire will go out."The chemist says, "No! No! I know what to do! We must cut off the supply of oxygen so that the fire will go out due to lack of one of the reactants."While the physicist and chemist debate what course to take, they both are alarmed to see the statistician running around the room starting other fires. They both scream, "What are you doing?"To which the statistician replies, "Trying to get an adequate sample size."

• Theorem: n=n+1
  
  Proof:
  (n+1)^2 = n^2 + 2*n + 1
  
  Bring 2n+1 to the left:
  (n+1)^2 - (2n+1) = n^2
  
  Substract n(2n+1) from both sides and factoring, we have:
  (n+1)^2 - (n+1)(2n+1) = n^2 - n(2n+1)
  
  Adding 1/4(2n+1)^2 to both sides yields:
  (n+1)^2 - (n+1)(2n+1) + 1/4(2n+1)^2 = n^2 - n(2n+1) + 1/4(2n+1)^2
  
  This may be written:
  [ (n+1) - 1/2(2n+1) ]^2 = [ n - 1/2(2n+1) ]^2
  
  Taking the square roots of both sides:
  (n+1) - 1/2(2n+1) = n - 1/2(2n+1)
  
  Add 1/2(2n+1) to both sides:
  n+1 = n
  
  

• There was this statistics student who, when driving his car, would always accelerate hard before coming to any junction, whizz straight over it , then slow down again once he’d got over it. One day, he took a passenger, who was understandably unnerved by his driving style, and asked him why he went so fast over junctions. The statistics student replied, “Well, statistically speaking, you are far more likely to have an accident at a junction, so I just make sure that I spend less time there.”

  Submitted by vicky.

• Math problems? Call 1-800-[(10x)(13i)^2]-[sin(xy)/2.362x].
  
  If parallel lines meet at infinity - infinity must be a very noisy place with all those lines crashing together!
  
  Maths Teacher: Now suppose the number of sheep is x...
  Student: Yes sir, but what happens if the number of sheep is not x?
  
  Zenophobia: the irrational fear of convergent sequences.
  
  Philosophy is a game with objectives and no rules. Mathematics is a game with rules and no objectives.
  
  If I had only one day left to live, I would live it in my statistics class: it would seem so much longer.
  
  

• "First and above all he was a logician. At least thirty-five years of the half-century or so of his existence had been devoted exclusively to proving that two and two always equal four, except in unusual cases, where they equal three or five, as the case may be." -- Jacques Futrelle, "The Problem of Cell 13"
  
  Most mathematicians are familiar with -- or have at least seen references in the literature to -- the equation 2 + 2 = 4. However, the less well known equation 2 + 2 = 5 also has a rich, complex history behind it. Like any other complex quantitiy, this history has a real part and an imaginary part; we shall deal exclusively with the latter here.
  
  Many cultures, in their early mathematical development, discovered the equation 2 + 2 = 5. For example, consider the Bolb tribe, descended from the Incas of South America. The Bolbs counted by tying knots in ropes. They quickly realized that when a 2-knot rope is put together with another 2-knot rope, a 5-knot rope results.
  
  Recent findings indicate that the Pythagorean Brotherhood discovered a proof that 2 + 2 = 5, but the proof never got written up. Contrary to what one might expect, the proof's nonappearance was not caused by a cover-up such as the Pythagoreans attempted with the irrationality of the square root of two. Rather, they simply could not pay for the necessary scribe service. They had lost their grant money due to the protests of an oxen-rights activist who objected to the Brotherhood's method of celebrating the discovery of theorems. Thus it was that only the equation 2 + 2 = 4 was used in Euclid's "Elements," and nothing more was heard of 2 + 2 = 5 for several centuries.
  
  Around A.D. 1200 Leonardo of Pisa (Fibonacci) discovered that a few weeks after putting 2 male rabbits plus 2 female rabbits in the same cage, he ended up with considerably more than 4 rabbits. Fearing that too strong a challenge to the value 4 given in Euclid would meet with opposition, Leonardo conservatively stated, "2 + 2 is more like 5 than 4." Even this cautious rendition of his data was roundly condemned and earned Leonardo the nickname "Blockhead." By the way, his practice of underestimating the number of rabbits persisted; his celebrated model of rabbit populations had each birth consisting of only two babies, a gross underestimate if ever there was one.
  
  Some 400 years later, the thread was picked up once more, this time by the French mathematicians. Descartes announced, "I think 2 + 2 = 5; therefore it does." However, others objected that his argument was somewhat less than totally rigorous. Apparently, Fermat had a more rigorous proof which was to appear as part of a book, but it and other material were cut by the editor so that the book could be printed with wider margins.
  
  Between the fact that no definitive proof of 2 + 2 = 5 was available and the excitement of the development of calculus, by 1700 mathematicians had again lost interest in the equation. In fact, the only known 18th-century reference to 2 + 2 = 5 is due to the philosopher Bishop Berkeley who, upon discovering it in an old manuscript, wryly commented, "Well, now I know where all the departed quantities went to -- the right-hand side of this equation." That witticism so impressed California intellectuals that they named a university town after him.
  
  But in the early to middle 1800's, 2 + 2 began to take on great significance. Riemann developed an arithmetic in which 2 + 2 = 5, paralleling the Euclidean 2 + 2 = 4 arithmetic. Moreover, during this period Gauss produced an arithmetic in which 2 + 2 = 3. Naturally, there ensued decades of great confusion as to the actual value of 2 + 2. Because of changing opinions on this topic, Kempe's proof in 1880 of the 4-color theorem was deemed 11 years later to yield, instead, the 5-color theorem. Dedekind entered the debate with an article entitled "Was ist und was soll 2 + 2?"
  
  Frege thought he had settled the question while preparing a condensed version of his "Begriffsschrift." This condensation, entitled "Die Kleine Begriffsschrift (The Short Schrift)," contained what he considered to be a definitive proof of 2 + 2 = 5. But then Frege received a letter from Bertrand Russell, reminding him that in "Grundbeefen der Mathematik" Frege had proved that 2 + 2 = 4. This contradiction so discouraged Frege that he abandoned mathematics altogether and went into university administration.
  
  Faced with this profound and bewildering foundational question of the value of 2 + 2, mathematicians followed the reasonable course of action: they just ignored the whole thing. And so everyone reverted to 2 + 2 = 4 with nothing being done with its rival equation during the 20th century. There had been rumors that Bourbaki was planning to devote a volume to 2 + 2 = 5 (the first forty pages taken up by the symbolic expression for the number five), but those rumor remained unconfirmed. Recently, though, there have been reported computer-assisted proofs that 2 + 2 = 5, typically involving computers belonging to utility companies. Perhaps the 21st century will see yet another revival of this historic equation.
  
  The above was written by Houston Euler.
  
  

• Math tells us three of the saddnest love stories:1)Tangent lines who had one chance to meet and then parted forever.2)Parallel lines who were never meant to meet.3)Asymptotes who can get closer and closer but will never be together.

• Theorem: 1$ = 1c.
  Proof:
  And another that gives you a sense of money disappearing.

  1$ = 100c
  = (10c)^2
  = (0.1$)^2
  = 0.01$
  = 1c

  Here $ means dollars and c means cents. This one is scary in that I have seen PhD’s in math who were unable to see what was wrong with this one. Actually I am crossposting this to sci.physics because I think that the latter makes a very nice introduction to the importance of keeping track of your dimensions.

  Submitted by vicky.

• Theorem: 4 = 5
  Proof:
  -20 = -20
  16 - 36 = 25 - 45
  4^2 - 9*4 = 5^2 - 9*5
  4^2 - 9*4 + 81/4 = 5^2 - 9*5 + 81/4
  (4 - 9/2)^2 = (5 - 9/2)^2
  4 - 9/2 = 5 - 9/2
  4 = 5
  
  

• A helium molecule walks in afterwards. The bellhop asks if he needs any help.Helium doesn't react.

• Son: Dad, it's so cold in here!Father: Go stand in the corner.Son: Why?Father: The corner is 90 degrees.

• An engineer, a physicist, and a mathematician are trying to set up a fenced-in area for some sheep, but they have a limited amount of building material. The engineer gets up first and makes a square fence with the material, reasoning that it's a pretty good working solution. "No no," says the physicist, "there's a better way." He takes the fence and makes a circular pen, showing how it encompasses the maximum possible space with the given material.
  
  Then the mathematician speaks up: "No, no, there's an even better way." To the others' amusement he proceeds to construct a little tiny fence around himself, then declares:
  
  "I define myself to be on the outside."
  
  

• Theorem: All positive integers are equal.
  
  Proof: Sufficient to show that for any two positive integers, A and B, A = B.
  
  Further, it is sufficient to show that for all N > 0, if A and B (positive integers) satisfy (MAX(A, B) = N) then A = B.
  
  Proceed by induction.
  
  If N = 1, then A and B, being positive integers, must both be 1. So A = B.
  
  Assume that the theorem is true for some value k. Take A and B with MAX(A, B) = k+1. Then MAX((A-1), (B-1)) = k. And hence (A-1) = (B-1). Consequently, A = B.
  
  

• Why did I divide sin by tan? Just cos.

• Hello, this is probably 438-9012, yes, the house of the famous statistician. I'm probably not at home, or not wanting to answer the phone, most probably the latter, according to my latest calculations. Supposing that the universe doesn't end in the next 30 seconds, the odds of which I'm still trying to calculate, you can leave your name, phone number, and message, and I'll probably phone you back. So far the probability of that is about 0.645. Have a nice day.
  
  

• Equation Men = eat + sleep + earn moneyDonkeys = eat + sleepTherefore,Men = Donkeys + earn moneyTherefore,Men - earn money = DonkeysIn other words,Men that don't earn money = Donkeys

• "Psst, c'mere," said the shifty-eyed man wearing a long black trenchcoat, as he beckoned me off the rainy street into a damp dark alley. I followed.
  
  "What are you selling?" I asked.
  
  "Geometrical algebra drugs."
  
  "Huh!?"
  
  "Geometry drugs. Ya got your uppers, your downers, your sidewaysers, your inside-outers..."
  
  "Stop right there," I interrupted. "I've never heard of inside-outers."
  
  "Oh, man, you'll love 'em. Makes you feel like M.C. ever-lovin' Escher on a particularly weird day."
  
  "Go on..."
  
  "OK, your inside-outers, your arbitrary bilinear mappers, and here, heh, here are the best ones," he said, pulling out a large clear bottle of orange pills.
  
  "What are those, then?" I asked.
  
  "Givens transformers. They'll rotate you about more planes than you even knew existed."
  
  "Sounds gross. What about those bilinear mappers?"
  
  "There's a whole variety of them. Here's one you'll love -- they call it 'One Over Z' on the street. Take one of these little bad boys and you'll be on speaking terms with the Point at Infinity."
  
  

• Student: What’s infinity? Math Teacher: Think of a number. Student: Okay, I’ve got one. Teacher: Good. That’s not it.

• A shoe seller meets a mathematician and complains that he does not know what size shoes to buy. “No problem,” says the mathematician, “there is a simple equation for that,” and he shows him the Gaussian normal distribution. The shoe seller stares some time at the equation and asks, “What is that symbol?” “That is the Greek letter pi.” “What is pi?” “That is the ratio between the circumference and the diameter of a circle.” Upon this the shoe seller cries out: “What does a circle have to do with shoes??”

  Submitted by vicky.

• Q: What did one math book say to the other? A: Don't bother me I've got my own problems!

• Q: How do you make seven an even number?A: Take the s out!

• A chemist, a physicist, and a mathematician are stranded on an island when a can of food rolls ashore. The chemist and the physicist comes up with many ingenious ways to open the can. Then suddenly the mathematician gets a bright idea: "Assume we have a can opener..."

• I used to think maths was useless, but then one day I realised that decimals had a point.

• Maths is like s*x...ADD the bedMINUS the clothesDIVIDE the legsand pray you don't MULTIPLY.

• If I had only one day left to live, I would live it in my math class: it would seem so much longer.

• Three statisticians go out hunting together. After a while they spot a solitary rabbit. The first statistician takes aim and overshoots. The second aims and undershoots. The third shouts out "We got him!"

• Q: Why do you rarely find mathematicians spending time at the beach? A: Because they can divide sin and cosine to get a tan!

• Theorem: 1$ = 10 cent
  Proof:
  We know that $1 = 100 cents
  Divide both sides by 100
  $ 1/100 = 100/100 cents
  => $ 1/100 = 1 cent
  Take square root both side
  => squr($1/100) = squr (1 cent)
  => $ 1/10 = 1 cent
  Multiply both side by 10
  => $1 = 10 cent

  Submitted by vicky.

• 1. Ten percent of all car thieves are left-handed
  2. All polar bears are left-handed
  1=2. If your car is stolen, there’s a 10 percent chance it was taken by a Polar bear

  1. 39 percent of unemployed men wear spectacles
  2. 80 percent of employed men wear spectacles
  1=2. Work stuffs up your eyesight

  1. All dogs are animals
  2. All cats are animals
  1=2. Therefore, all dogs are cats

  Submitted by vicky.

• Q:Why do they never serve beer at a math party?A:Because you can't drink and derive...

• Q: What is the most erotic number? A: 2110593! Q: Why? A: When 2 are 1 and don't pay at10tion, they'll know within 5 weeks whether or not, after 9 months, they'll be 3.

• A mathematician and a non-mathematician are sitting in an airport hall waiting for their flight to go. The non has terrible flight panic.
  
  "Hey, don't worry, it's just every 10000th flight that crashes."
  
  "1:10000? So much? Then it surely will be mine!"
  
  "Well, there is an easy way out. Simply take the next plane. It's much more probable that you go from a crashing to a non-crashing plane than the other way round. So you are already at 1:10000 squared."
  
  

• A very large mathematical convention was held in Las Vegas. The conventioneers filled two hotels, each with an infinite number of rooms. The hotels were across the street from each other and were owned by brothers. One evening, while everyone was out at a bar-b-que, one of the hotels burned to the ground. The brothers got together and worked out a plan. In the remaining hotel, they moved all guests to twice their room number -- room 101 moved to 202, room 1234 moved to room 2468, etc. Then all the odd number rooms were empty, and there were an infinite number of odd rooms. So the guests from the other hotel moved into them.
  
  

• There was a statistician that drowned crossing a river... It was 3 feet deep on average.

• Theorem: 1 = -1
  Proof:
  1 = sqrt(1) = sqrt(-1 * -1) = sqrt(-1) * sqrt(-1) = 1^ = -1
  
  Also one can disprove the axiom that things equal to the same thing are equal to each other.
  
  1 = sqrt(1)
  -1 = sqrt(1)
  Therefore 1 = -1
  
  As an alternative method for solving:
  
  Theorem: 1 = -1
  Proof:
  x=1
  x^2=x
  x^2-1=x-1
  (x+1)(x-1)=(x-1)
  (x+1)=(x-1)/(x-1)
  x+1=1
  x=0
  0=1
  => 0/0=1/1=1
  
  

• A football coach walked into the locker room before a game, looked over to his star player and said, “I’m not supposed to let you play since you failed math, but we need you in there. So, what I have to do is ask you a math question, and if you get it right, you can play.”

  The player agreed, and the coach looked into his eyes intently and asks, “Okay, now concentrate hard and tell me the answer to this. What is two plus two?”

  The player thought for a moment and then he answered, “4?”

  “Did you say 4?” the coach exclaimed, excited that he got it right.

  At that, all the other players on the team began screaming, “Come on coach, give him another chance!”

  Submitted by vicky.

• Theorem: e=1
  Proof:
  2*e = f
  2^(2*pi*i)e^(2*pi*i) = f^(2*pi*i)
  e^(2*pi*i) = 1
  
  Therefore:
  2^(2*pi*i) = f^(2*pi*i)
  2=f
  Thus:
  e=1
  
  

• Theorem: 1$ = 1c.
  Proof:
  And another that gives you a sense of money disappearing.
  
  1$ = 100c
  = (10c)^2
  = (0.1$)^2
  = 0.01$
  = 1c
  
  Here $ means dollars and c means cents. This one is scary in that I have seen PhD's in math who were unable to see what was wrong with this one. Actually I am crossposting this to sci.physics because I think that the latter makes a very nice introduction to the importance of keeping track of your dimensions.
  
  

• A mathematician and an engineer agreed to take part in an experiment. They were both placed in a room and at the other end was a beautiful naked woman on a bed. The experimenter said every 30 seconds they would be allowed to travel half the distance between themselves and the woman. The mathematician said "this is pointless" and stormed off. The engineer agreed to go ahead with the experiment anyway. The mathematician exclaimed on his way out "don't you see, you'll never actually reach her?". To which the engineer replied, "so what? Pretty soon I'll be close enough for all practical purposes!"

• ...and then the devil said, "Let's put the alphabet into mathematics."

• Q: You know that awesome feeling, when you finally understand math?A: Me neither.

• Prove that the crocodile is longer than it is wide.
  
  Lemma 1. The crocodile is longer than it is green: Let's look at the crocodile. It is long on the top and on the bottom, but it is green only on the top. Therefore, the crocodile is longer than it is green.
  
  Lemma 2. The crocodile is greener than it is wide: Let's look at the crocodile. It is green along its length and width, but it is wide only along its width. Therefore, the crocodile is greener than it is wide.
  
  From Lemma 1 and Lemma 2 we conclude that the crocodile is longer than it is wide.
  
  

• Theorem: All numbers are equal.
  Proof: Choose arbitrary a and b, and let t = a + b. Then
  
  a + b = t
  (a + b)(a - b) = t(a - b)
  a^2 - b^2 = ta - tb
  a^2 - ta = b^2 - tb
  a^2 - ta + (t^2)/4 = b^2 - tb + (t^2)/4
  (a - t/2)^2 = (b - t/2)^2
  a - t/2 = b - t/2
  a = b
  
  So all numbers are the same, and math is pointless.
  
  

• Q: Why did the mathbook kill himself?A: Because nobody understood him.

• Q. What mode do you use in maths?A. Multi-plyers.