# LaTeX/Math jokes [closed]

Lighten up a bit guys. How about the following

\documentclass{article}
\usepackage{graphicx}
\begin{document}
If~~$\displaystyle\lim_{x\rightarrow8}\frac{1}{x{-}8}=\infty$
~~then~~$\displaystyle\lim_{x\rightarrow5}\frac{1}{x{-}5}=\rotatebox{90}{5}$
\end{document}


Which gives — Can anyone give me some nice Tikz of PStricks code for the following I am sure there there must be more Latex humor out there, even among the Germans ;-)

• I made it CW because it asks about more contributions which wouldn't fit in the normal Q&A scheme. – Martin Scharrer May 16 '11 at 7:21
• @Danie: You should add any new examples that you think of as answers rather than editing the question. – Andrew Stacey May 16 '11 at 8:41
• 1+1=3 for sufficient large 1s and sufficient small 3s. – Martin Scharrer May 16 '11 at 10:55
• I've also voted to close now. The idea I had was that the "jokes" should reveal something about TeX, such as illustrating a technique. Some answers did that, but the longer the question stays open then the less likely it is that new answers will continue in that vein. So while I enjoyed it when it was asked, I think that it had a finite life and it is now time to close it. – Andrew Stacey May 29 '11 at 20:21
• Code and Output – kiss my armpit Aug 10 '12 at 6:36

\font\donteveruseoutsidecartoons="Comic Sans MS" at 14pt
\font\donteveruseoutsidecartoonstwo="Comic Sans MS/IB:slant=.3pt" at 22pt
\input tikz
\usetikzlibrary{shapes.callouts,positioning}
\tikzpicture[mycallout/.style={draw,ellipse callout,inner sep=1.2ex,
callout relative pointer={#1}}]
\node[mycallout={(.5cm,-.5cm)}] (ico) {\donteveruseoutsidecartoons Be rational};
\node[mycallout={(-.5cm,-.5cm)}, right=of ico] (pco) {\donteveruseoutsidecartoons Get real};
\node[below=.1ex of ico.pointer] {\donteveruseoutsidecartoonstwo i};
\node[below left=.1ex of pco.pointer] {\donteveruseoutsidecartoonstwo π\vphantom(};
\endtikzpicture
\bye • especially for the font names – Andrew Stacey May 16 '11 at 7:40
• This is very good. People may not realize it, but all this stuff is very usefull to make boring engineering or math lectures a little bit more interesting. – Danie Els May 16 '11 at 8:00
• @Danie: Completely agree. And often (speaking as a lecturer) it's not until I see an example that I realise that such things are possible so there is certainly potential value in this question. – Andrew Stacey May 16 '11 at 8:28
• –1 for the font. ;-) – Konrad Rudolph May 16 '11 at 11:53
• @Konrad --- surely that should be \mathrm{e}^{\mathrm{i}\pi} for the font? – Ian Thompson May 16 '11 at 15:59 \documentclass[a4paper,12pt]{article}
\usepackage[margin=1in]{geometry}

\usepackage{graphicx}
\usepackage{pgffor}
\pagestyle{empty}

\parindent=0pt
\begin{document}
\large\sffamily

\resizebox{\textwidth}{!}{The first 500 natural random numbers}

\vspace{1em}

\centerline{\LARGE For easy access listed in their natural order}
\bigskip

\par\noindent
\foreach \n in {1,...,500} {%
\makebox[1.8em][r]{\n}
}

\end{document}

• @ Martin Scharrer - I like this. Do you mind if I turn it into a natural number spotter's guide and stick it on wall? – Richard Terrett May 18 '11 at 8:29
• @Richard: Sure. Note I didn't came up with it. I saw this in my college in the math building once. – Martin Scharrer May 18 '11 at 8:32
\documentclass{article}
\usepackage{amsmath}

\begin{document}

Expand $(a+b)^n$:
\begin{gather*}
(a + b)^n\\
(a\ + \ b)^n\\
\end{gather*}

\end{document} EDIT: to Andrew:

\documentclass{article}

\newcount\mycntr

\begin{document}

Expand $(a+b)^n$:

\begin{center}
\mycntr=0
\ifnum\mycntr<40
$(a\hskip\mycntr pt +\hskip\mycntr pt b)^n$\\
\repeat
\end{center}

\end{document}

• This one is epic. – Paulo Cereda May 16 '11 at 16:31
• Aw, come on ... no iteration? Let's have a more programmatic version of this one! – Andrew Stacey May 16 '11 at 17:45
• @Andrew Stacey: done. Personally I prefer the non-iterative version. – Gonzalo Medina May 16 '11 at 18:09
• I prefer expanding the expression in 2 dimension. – xport May 27 '11 at 7:05

A silly one I found on a blog: \documentclass{article}
\usepackage{graphicx}
\usepackage{cancel}

\begin{document}

\begin{eqnarray*}
\frac{1}{n}\sin x & = & \mathrm{?} \\
\frac{1}{\cancel{n}} \mathrm{si}\cancel{\mathrm{n}} ~x & = & \mathrm{?} \\
\mathrm{six} & = & 6
\end{eqnarray*}

\end{document}


This one from xkcd is a classic: \documentclass{article}
\usepackage{graphicx}
\usepackage{amsmath}

\begin{document}

$\begin{bmatrix} \cos 90^{\circ} & \sin 90^{\circ}\\ -\sin 90^{\circ} & \cos 90^{\circ} \end{bmatrix} \begin{bmatrix} a1 \\ a2 \end{bmatrix} =$
\rotatebox[origin=c]{270}{$\begin{bmatrix} a1 \\ a2 \end{bmatrix}$}

\end{document}


I never played with tikz before, so that's my first attempt. I simply love the following joke:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations.pathmorphing}
\usepackage{frcursive}
\begin{document}

Find $x$.

\begin{tikzpicture}
\draw (0,0) -- (4,0) node[midway,below] {4 cm}
-- (4,3) node[midway,right] {3 cm}
-- (0,0) node[midway,left,circle,draw=blue,decorate,decoration={random steps,segment length=1pt,amplitude=0.5pt}]{$x$}
-- (4,0) rectangle (3.7,0.3)
-- cycle;
\draw (0.4,0) arc (0:30:0.5);
\draw (4,2.6) arc (270:226:0.5);
\draw (1,2.1) node []{\color{blue}\fontfamily{frc}\selectfont{It's here!}};
\end{tikzpicture}

\end{document}


The result: • You should also draw a blue circle around x. Just add circle,draw=blue to its node. I might need to set the color of the content back to black. – Martin Scharrer May 16 '11 at 15:22
• @Martin Scharrer: Thanks a lot, I updated both code and image. It looks way better that way! =) – Paulo Cereda May 16 '11 at 15:59
• The circle could use a jittering line (it’s hand-drawn, right?). You can use the random steps decoration for that. – Konrad Rudolph May 16 '11 at 16:07
• @Konrad Rudolph: Thanks, I updated the code again. You guys are awesome! =) – Paulo Cereda May 16 '11 at 16:24
• A pedant's note: you could use a \, or \SI from siunitx to typeset the lengths. – Andrey Vihrov May 17 '11 at 15:11

Mathematicians do it in \LaTeX.

I'll get my coat.

To all my Australian friends:

\documentclass{article}
\usepackage{graphicx}
\begin{document}
\noindent Are there any \raisebox{1ex}{\rotatebox[origin=B]{180}{Australians}}
here mate?\\ Hang on tight!
\end{document} Here's another joke I remember:

\documentclass{article}

\usepackage[T1]{fontenc}
\usepackage[light,math]{anttor}

\begin{document}

Let $\displaystyle f(a) = \sqrt[n]{e^x}$.

\begin{minipage}{0.5\textwidth}
\begin{eqnarray*}
\lim_{t\rightarrow\infty} f(a) - \frac{i}{f(t)} & = & \frac{d}{dx} f(u) \\
\lim_{t\rightarrow\infty} f(a) - \frac{i}{\infty} & = & \frac{d}{dx} f(u) \\
\lim_{t\rightarrow\infty} f(a) - 0 & = & \frac{d}{dx} f(u)
\end{eqnarray*}
\end{minipage}

\bigskip

Then

\begin{minipage}{0.5\textwidth}
\begin{eqnarray*}
\sqrt[n]{e^x} & = & \frac{d}{dx} f(u) \\
(\sqrt[n]{e^x})^n & = & \frac{d}{dx} f(u)^n \\
e^x & = & \frac{d}{dx} f(u)^n \\
\int e^x & = & f(u)^n
\end{eqnarray*}
\end{minipage}

\end{document}


The output: • You deliberately made many typos? – xport May 27 '11 at 7:07
• Sadly, no. I simply wrote it as it is from a PNG image. =) – Paulo Cereda May 27 '11 at 9:11

Riffing on the "Australians" joke, borrowing from this answer. • I get the original joke, but fail to see it in the alternations. – Martin Scharrer May 16 '11 at 11:31
• @Martin it's my tribute to Stewart Lee – Seamus May 16 '11 at 11:40