What is the formula for the volume of a thick crust pizza?

[soroban]

"Hey, old timer! . Lived here all your life?"

"Not yet."

 

[topsquark]

View attachment 4296
(An excerpt from my thesis defense.)

-Dan

 

[soroban]

Karaoke bars combine our two greatest evils:

people who shouldn't drink and people who shouldn't sing.

 

[soroban]

Does the name Pavlov ring a bell?

 

[Evgeny.Makarov]

Newton: If you mess with me, expect my revenge.
Secretary: But, sir, we can't publish that.
Newton: OK then, write this: For every action there is an equal and opposite reaction.

 

[Evgeny.Makarov]

Some student answers during exams.

• The expression $\pi=\frac{C}{d}$ means that $\pi$ is directly proportional to the circumference and inversely proportional to the diameter.
• The number of elements on the main diagonal of a square matrix of size $n$ is $n\sqrt{2}$.
• A function is continuous if there exists every epsilon…

 

[Evgeny.Makarov]

As a preamble to the following story I'd like to remind you about the role the year 1917 played in the history of Russia. That year two revolutions happened in Russia: the first resulted in the abdication of the tsar, and the second brought the Bolshevik rule and led to the appearance of the Soviet Union. The anniversaries of the October revolution (even though it happened in November according to the Gregorian calendar) were one of three or four major holidays in the Soviet Union.

The story was told by Vladimir Tikhomirov, a mathematician working in the area of functional analysis and mathematical optimization, a distinguished professor of Moscow State University. It's about Dmitri Menshov, one of the first Soviet mathematicians.

Once in the 1960s there was a meeting between students and faculty of the department of functional analysis. Menshov was asked to speak about the origin of the Moscow mathematical school. This is what he said.

"In 1914 I was admitted to Moscow University. Prof. Nikolai Luzin then lived abroad, but he arranged with Prof. Dmitri Egorov that they would organize a research seminar for students. And Prof. Egorov did start this seminar in 1914. It was devoted to numerical series. The following year Prof. Lusin returned to Moscow and started to supervise the seminar himself. In 1915 we studied functional series, and in 1916, orthogonal series.

And then came 1917. It was a very memorable year of our lives. That year happened an event that influenced our entire life: we started studying trigonometric series…"

 

[Evgeny.Makarov]

A constructivist's joke: A lemma is a theorem proved using the law of excluded middle.

Zenophobia: the irrational fear of converging sequences.

Evaluate this expression: $7(3^2-5)-7+3$. You may be surprised to discover that the result is 4!

My PIN code is the last 4 digits of $\pi$.

 

[Deveno]

Evaluate this expression: $7(3^2-5)-7+3$. You may be surprised to discover that the result is 4!

When I divided it by 4, I got 3!

 

[Evgeny.Makarov]

It's such a unique number that I can even divide it by 0!

 

[Evgeny.Makarov]

Once you've read a dictionary, every other book is just a remix.

Yes, English can be weird. It can be understood through tough thorough thought, though.

"This does not count!", cried children looking at the set of real numbers.

The equation was stolen by two unknowns.

This dialog happened during a job interview.
Q: If you were told to develop a perpetual motion machine, where would you start?
A: I'd study successful related projects.

 

[Evgeny.Makarov]

"Google search engine receives too many requests from your IP address. This is a typical behavior of a robot. To prove that you are not a robot, injure a human being or allow a human being to come to harm through inaction."

Quantum children do their homework only while being watched.

Romans considered mathematics an easy subject. They always had X equal to 10.

 

[Evgeny.Makarov]

 

[Evgeny.Makarov]

One student claimed that \(\displaystyle \ln0=e\). To prove it, he typed \(\displaystyle \ln\) and \(\displaystyle 0\) on a calculator and got the answer \(\displaystyle e\).

Another student had to prove that $\sqrt{2}+\sqrt{3}$ is irrational. His reasoning was as follows. $\sqrt{2}=1.41$ and $\sqrt{3}=1.73$. Hence, $\sqrt{2}+\sqrt{3}=3.14=\pi$, and it is known that $\pi$ is irrational.

Q: What are regular expressions?
A: These are expressions regularly uttered by programmers during coding.

 

[Farmtalk]

Opinions without pi are just onions.

 

[Evgeny.Makarov]

You might be a mathematician if you think that fog is a composition.

Old Macdonald had a form; $e_i\land e_i = 0$.

To some degree, 2 is also an 8. (Not sure if this is translatable into English.)

John + Sarah = love.
Error: left operand must be an l-value.

 

[Joppy]

Not sure if this is in here already :p.

A drunk man will find his way home, but a drunk bird may get lost forever - Shizuo Kakutani

 

[Monoxdifly]

Never just use the number 2 as example because:
2 + 2 = 4
2 x 2 = 4
2² = 4
By that logic, children who haven't grasped the concept of multiplication and exponent will think that:
3 + 3 = 6
3 x 3 = 6
3³ = 6

 

[Joppy]

Never just use the number 2 as example because:
2 + 2 = 4
2 x 2 = 4
2² = 4
By that logic, children who haven't grasped the concept of multiplication and exponent will think that:
3 + 3 = 6
3 x 3 = 6
3³ = 6

I'm not sure if I should laugh or be worried! xD

 

[Evgeny.Makarov]

View attachment 6654

 

[Evgeny.Makarov]

1. Beethoven, being deaf, could write wonderful symphonies. Why can't I, being dumb, write good research papers?

2. One couple used to stop at a certain gas station and occasionally used their air machine to fill their car's tires. Once they discovered that pumping air was no longer free.

Wife: "Why in the world did they start charging for air?"
Husband: "Inflation".

3. I gave the following problem as a part of the exam on the theory of programming languages. The variants were taken from a forum where math teachers discuss mistakes their students make on the Russian equivalent of SAT.

Factor out the sine in the expression \(3\sin x -4\sin^3x\).

1. $\sin x (3-4^3)$
2. $\sin x (3-4n^2)$
3. $(\lambda x.\, 3x - 4x^3) (\sin x)$
4. $\sin (3 x - 4^3 x)$

 

[Monoxdifly]

[*] $(\lambda x.\, 3x - 4x^3) (\sin x)$

This. How did they get that lambda there?

 

[Evgeny.Makarov]

This refers to the so-called lambda calculus. It's a formal system whose goal is to distinguish function as a mapping and the value of a function at some point. In calculus one often sees phrases like "The function $f(x)$ is differentiable at $x_0$", where $f(x)$ means not the value of $f$ at point $x$, but the function as a whole. In lambda calculus, $x^2$ means the square of some number $x$, but $\lambda x.\,x^2$ is a function that maps any $x$ to $x^2$. In addition to notation for functions, lambda calculus has a rule of simplification: $(\lambda x.\,t)s$ can be rewritten to the result of the substitution of $s$ for $x$ in $t$. This makes sense: in programming terminology, the actual parameter $s$ is substituted for a formal parameter $x$ in the body $t$ of the function. In particular, $(\lambda x.\, 3x - 4x^3) (\sin x)$ reduces to $3\sin x-4\sin^3x$.

 

[I like Serena]

"The function $f(x)$ is differentiable at $x_0$", where $f(x)$ means not the value of $f$ at point $x$, but the function as a whole.

Interesting. I didn't realize the role of lambda calculus in this context before.
I do realize that formally it should be "The function $f$ is differentiable at $x_0$".
Or alternatively, "The function given by $x \mapsto f(x)$ is differentiable at $x_0$".
I'm only realizing just now that the second form matches the lambda form ($\lambda x. f(x)$), while in the first form $f$ is an unspecified lambda form.

 

[Evgeny.Makarov]

From here.

 

[Wilmer]

Mary is realllllly skinny...

How skinny is she?

She swallowed an olive and 2 guys left town!

 

[Ackbach]

Person A: Knock, knock. Race condition. Who's there?

 

[Evgeny.Makarov]

Person A: Knock, knock. Race condition. Who's there?

A similar joke.

TV anchor: We present our reporter John Smith at the site of the Large Hadron Collider, where an accident occurred this morning.
Reporter: I am hearing you well.
Anchor: John, can you here us?

"Tomb" is pronounced "toom", and "womb" is pronounced "woom". Why isn't "bomb" pronounced "boom"?

I like silly jokes like the following.

"Guess what?"
"What?"
"Good guess."

 

[Wilmer]

Mary is realllllly skinny...

How skinny is she?

She swallowed an olive and 2 guys left town!

Looks like nobody "got" that one...
She was so skinny that the swallowed olive made her appear pregnant!

 

[MarkFL]

View attachment 8114

 

[Wilmer]

What well known expression does this represent:

...9,8,7,6,5,4,3,2,1,

 

[I like Serena]

What well known expression does this represent:

...9,8,7,6,5,4,3,2,1,

Either the launch to the moon, or a government official counting his cards (we're just missing king, queen, jack, and 10).

 

[Wilmer]

Good try, but no ceegar!

Clue (word lengths): --- --'-- ---- ------- --- !

 

[Wilmer]

Anutter clue: y-- a-'-- s--- n------ y--

 

[Wilmer]

Before I forget it: you ain't seen nothing yet!