Posts tagged ‘integral’

When Math Falls into the Wrong Hands

My brother-in-law recently forwarded an email that contained a lot of images plucked from various degenerate corners of the internet, and he suggested that this one could go into my next book:

image of a handwritten note, with a definite integral given as the PIN code for an ATM card

I suppose it’s funny enough, and I guess it’s technically a math joke, but there’s a problem.

It doesn’t work.

I know, I know. Most people just read the joke, get the humor that the note’s author has used some odious expression to represent the PIN code, and go on about their day. Plus, I’ve heard that less than 1% of the world’s population has taken calculus, so there aren’t too many people who could actually check the math. Not to mention, how many of them would care enough to do so?

Uh… I can think of at least one person who cares enough.

Venn diagram with circle for knows calculus, another circle for cares about the math in jokes, and contains the author's image in the intersection

While it’s certainly egotistical to think that I’m the only one in the intersection, it’s likely offensive to include anyone in the intersection who really wouldn’t want to be. So apologies to Matt Parker, Des McHale, Colin Adams, Ed Burger, or any of the other funny math folks who think they should have been included.

Anyway, where was I? Oh, right. Bad math.

The definite integral in the joke sent by my brother-in-law doesn’t yield a four-digit positive integer.

calculation from Wolfram Alpha showing the value of a definite integralIn fact, it yields a very irrational number with a lot of digits:


So unless the PIN code for that bank card has an infinity of digits, well, this is going to be problematic.

I propose, instead, that the joke be rewritten to use the following:

definite integral of x-squared dx from 1 to 19Would it be less funny? Probably. But at least it’d be accurate.

Not to mention, it would be a significantly more fair to Darling. Honestly, no one should ever have to do integration by substitution.

February 25, 2019 at 7:31 am 2 comments

Beer and Calculus Don’t Mix — Don’t Drink and Derive!

After Franklin Delano Roosevelt signed the Cullen-Harrison Act to end prohibition, sales of beer in the U.S. became legal on April 7, 1933. (Not a moment too soon, I might add. My father was born on April 12, 1933, and he surely gave my grandmother plenty of reasons to imbibe!) Consequently, April 7 is now known as National Beer Day, and April 6 is unofficially New Beer’s Eve.

A definite integral walks into a bar and orders five pints of Guinness. The bartender pours them, and the definite integral finishes them one after the other. “Can I have five more?” he asks.

The bartender says, “Don’t you think you’ve had enough?”

“Don’t worry about me,” says the integral. “I know my limits.”

Someday, I hope to meet the guy who invented beer — and buy that man a beer!

Finally, a logic puzzle with a solution that seems appropriate…

You come to a fork in the road. One branch leads to the City of Truth, and the other leads to the City of Deceit. You can ask the person stationed at the fork in the road one simple question to help you determine the correct path to the City of Truth. If the person is from the City of Truth, he will answer your question honestly; if he is from the City of Deceit, he will answer your question dishonestly. What question should you ask?

“Did you know they’re serving free beer in the City of Truth?”

The truth‑teller will say, “No!” and run to get a beer. The liar will say, “Yes!” and run to get a beer. Either way, follow him.

April 6, 2011 at 12:41 am 4 comments

I Wanna Be Tangent to Your Curves, and Other Math Pick-Up Lines

Need help with chicks at the next math department mixer? Try a few of these…

I wish I were your derivative, so I could lie tangent to your curves.

I memorized the first 300 digits of π. If you gimme a chance, I bet I could memorize the first 7 digits of your phone number, too.

I wish I were your second derivative so I could investigate your concavities.

Hey baby, what’s your sine?

You’re a palindromic set of perfect squares: 36‑25‑36.

You are more fascinating than the Fundamental Theorem of Calculus.

I = { } when you’re not around.

I don’t like my current girlfriend. Mind if I do a you‑substitution?

Hey, baby… nice asymptote.

You may be out of my range, but I’d love to show you my domain.

I’ll take you to your limit if you show me your end behavior.

My love for you is a monotonically increasing.

I can take you to the limit as x → ∞.

No way! Your name is really Leslie? Look, I can spell your name on my calculator!

Your beauty cannot be spanned by a finite basis of vectors.

You’ve got more curves than a triple integral.

Warning: The following pick-up lines contain material that may be unsuitable for minors.

I need a little help with my calculus… can you integrate my natural log?

I wish I were a problem set, because then I’d be really hard, and you’d be doing me on the desk.

January 31, 2011 at 12:40 am Leave a comment

XXX Rated

Today is 10/10/10, which Julius Caesar and others might have written as X/X/X. In honor of the date, today’s post contains some XXX‑rated jokes. (Okay, not really. There is no pornography. But today’s jokes are slightly off‑color and probably not appropriate for the classroom. Then again, I know a high school teacher who used the following mnemonic to help students remember SOHCAHTOA: Sex Over Hot Coals Adds Heat To Ordinary Affection. So perhaps I don’t really know what is and isn’t classroom inappropriate.)

But before we get to the jokes, a math problem for you containing three 10’s. When the following expression is written in standard form, how many digits does it contain?


(By the way, for all you code geeks, that expression was done with straight HTML. No MathML required! It simply uses nested <sup> tags.)

 Okay, to the jokes…

How is sex like a fraction? It’s improper when the larger one is on top.

What is the square root of 69? Eight something.

What is 6.9? A good time interrupted by a period.

I was hanging out in an Internet cafe when my server went down on me.

Calculus teachers do it to the limit.
Statisticians probably do it.
Combinatorialists do it discretely.
Algebraists do it in groups.

No post about dirty math jokes would be complete without…

Speaking of integrals, here’s a half-assed integral:

And a slightly longer one…

The math professor explained to her students that there would be no acceptable excuse for missing the final exam. “Unless you or a loved one dies, I expect you to be here,” she told them. “No other excuse will suffice.”

“What about sexual exhaustion?” asked the class clown, which made several of the other students snicker.

“Sorry, Johnny,” the professor said. “You’ll just have to write with your other hand.”

Finally, I’ll leave you with my favorite dirty math problem, which I love mainly because of its subtlety:

A mother is 21 years older than her son. In 6 years, she will be 5 times as old as her son. Where is the father?

October 10, 2010 at 8:30 pm 12 comments

About MJ4MF

The Math Jokes 4 Mathy Folks blog is an online extension to the book Math Jokes 4 Mathy Folks. The blog contains jokes submitted by readers, new jokes discovered by the author, details about speaking appearances and workshops, and other random bits of information that might be interesting to the strange folks who like math jokes.

MJ4MF (offline version)

Math Jokes 4 Mathy Folks is available from Amazon, Borders, Barnes & Noble, NCTM, Robert D. Reed Publishers, and other purveyors of exceptional literature.

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