Bad Math Jokes

[DrClaude]

https://xkcd.com/2370/

 

[waternohitter]

Rolling back the years to a simpler time when Abbott and Costello taught us some real math:

So that's how you do the math. I learned a lot!

 

[mfb]

19 and 20 got into a fight. 21.

A more well-known variant: Why is 6 afraid of 7? Because 7 8 9.

And then there is that headline, of course: https://www.ntnews.com.au/news/northern-territory/one-tooth-free-for-fifes-hicks-sven-ate-nine-tench/news-story/9e51f18033a9f6c24a0f1a985b986ef0

 

[etotheipi]

If 2005 humour is still funny... the English cat 'one two three' and the French cat 'un deux trois' had a swimming race to decide after which country the Channel should be named. The un deux trois cat sank.

 

[fresh_42]

If 2005 humour is still funny... the English cat 'one two three' and the French cat 'un deux trois' had a swimming race to decide after which country the Channel should be named. The un deux trois cat sank.

But only because the one two three forth dived.

 

[DrGreg]

If 2005 humour is still funny... the English cat 'one two three' and the French cat 'un deux trois' had a swimming race to decide after which country the Channel should be named. The un deux trois cat sank.

That reminds me of the very first joke in the very first episode of Fawlty Towers

Manuel, the Spanish waiter, whose grasp of English is poor, is carrying three breakfast trays to the hotel rooms.

BASIL: Manuel, there's too much butter on those trays!

MANUEL: ¿Que?

BASIL: There's too much butter on those trays!

MANUEL: No, Mister Fawlty, is not "on doz trez", is "uno dos tres"!

 

[Vanadium 50]

Wonderful show: "Not pigs! Pigeon...like your English!"

 

[jack action]

Today's math problem:

If George is 68 and his girlfriend is 22, how much money does George have?

 

[fresh_42]

I still like best the shortest of all: Be $\varepsilon <0$.

 

[etotheipi]

 

[etotheipi]

 

[fresh_42]

View attachment 271448

And the most trivial version of it has even a special name $\int_a^b f(x)\,dx = F(a)-F(a)$.
I will never understand why this is fundamental and Stokes is not.

 

[mfb]

$\int_a^b f(x)\,dx = F(a)-F(b)$.

On the surface this one looks a bit ... disconnected.

 

[Ibix]

$\int_a^b f(x)\,dx = F(a)-F(a)$

If only that weren't a typo, integration would be a lot easier...

 

[jack action]

 

[benorin]

I loved that @jack action

 

[jack action]

 

[jack action]

 

[benorin]

 

[256bits]

New Math
To keep them occupied, the teacher asked the class to draw three pictures of their favourite numbers.
Next day, after class, she motioned Johnny to come to her desk and explain his nice pictures.

The first picture was of 9. How is that 9 she asked.
"It's tree + tree + tree", Johnny replied as if a matter of fact.

And the next one, of 99, was of some dusty looking trees.
"Gee teacher, that's dirty tree + dirty tree + dirty tree", replied Johnny, somewhat annoyed.

The third picture was of the dusty trees and some pigeons flying overhead.
"And this one is of a 100?", she quizzed.
"Don't you know anything teacher?", totally exasperated.
"Anyone knows that 100 is dirty tree and a turd + dirty tree and a turd + dirty tree and a turd!"

 

[Keith_McClary]

SMBC

 

[BWV]

 

[etotheipi]

$$2x = \frac{d}{dx}(x^2) = \frac{d}{dx} (\underbrace{x + \dots + x}_{x \, \mathrm{times}}) = \underbrace{1 + \dots + 1}_{x \, \mathrm{times}} = x$$Hence, $2=1$.

 

[DrGreg]

All numbers are equal! Let $a$ and $b$ be any two numbers and define$$
c = a + b.
$$Multiply both sides by $a-b$:$$
(a - b)c = (a - b)(a+b).
$$Expand:$$
ac - bc = a^2 - b^2.
$$Rearrange:$$
b^2 - bc = a^2 - ac.
$$Add $ab$ to both sides:$$
ab + b^2 - bc = a^2 + ab - ac.
$$Factorise:$$
(a+b-c)b = (a+b-c)a.
$$Cancel:$$
b=a
$$QED.

 

[etotheipi]

"You see officer, whilst it's true that I was going 80 mph on that dual carriageway, Dr Greg proved that in fact 80 = 70 and so, mathematically, this fine is unjustified..."

(...and if that fails, we can always change tack and assert that [to my knowledge] the highway code never specified the reference frame in which the speed is to be measured...)

 

[nuuskur]

Spoiler

$$2x = \frac{d}{dx}(x^2) = \frac{d}{dx} (\underbrace{x + \dots + x}_{x \, \mathrm{times}}) = \underbrace{1 + \dots + 1}_{x \, \mathrm{times}} = x$$Hence, $2=1$.

Hah, that made me chuckle. That's a cute attempt, though :D A lot of people might sleep on the $x$ times business.

 

[Ibix]

"You see officer, whilst it's true that I was going 80 mph on that dual carriageway, Dr Greg proved that in fact 80 = 70 and so, mathematically, this fine is unjustified..."

Judge: Excellent point, Mr Pi. So you will find it no greater hardship that I have doubled the fine.

 

[DrGreg]

$$2x = \frac{d}{dx}(x^2) = \frac{d}{dx} (\underbrace{x + \dots + x}_{x \, \mathrm{times}}) = \underbrace{1 + \dots + 1}_{x \, \mathrm{times}} = x$$Hence, $2=1$.

Corollary: All numbers are equal.

Proof: $$\begin{align*}
2 &= 1 \\
\implies 2(b-a) &= b-a \\
\implies b-a &= 0 \\
\implies a &= b \\
\end{align*}$$

 

[mfb]

If all numbers are equal then the Riemann hypothesis is both true and false.

* Every point is a root as every function value is equal to zero.
* There is no root outside the critical strip as every point of the domain is equal to the critical strip.

This might sound like a contradiction, but it just extends the original point by showing that also true=false.

 

[benorin]

All numbers are equal! Let $a$ and $b$ be any two numbers and define$$
c = a + b.
$$Multiply both sides by $a-b$:$$
(a - b)c = (a - b)(a+b).
$$Expand:$$
ac - bc = a^2 - b^2.
$$Rearrange:$$
b^2 - bc = a^2 - ac.
$$Add $ab$ to both sides:$$
ab + b^2 - bc = a^2 + ab - ac.
$$Factorise:$$
(a+b-c)b = (a+b-c)a.
$$Cancel:$$
b=a
$$QED.

One cannot cancel a zero factor

Spoiler: Can't think of it? I got you...

since c=a+b => a+b-c=0

 

[waternohitter]

 

[Fred Wright]

A passenger jet takes off from Warsaw. Suddenly both pilot and copilot suffer heart attacks. The stewardess panics and announces to the passengers, "Is there a doctor on board?" A man stands and says, "I know some first aid." She rushes him to the pilot's cabin where he discovers both pilot and copilot have died. She desperately cries, "You have to land the plane!" The man looks around and says, "I can't do that! I'm just a simple Pole on a complex plane."

 

[mfb]

It wouldn't help anyway. There is no path that leaves the complex plane!

 

[DrClaude]

 

[BWV]