I saw this symbol: $\underline{\big|6} $ in a question bank for a chapter of permutations and combinations. I have included the question from the book to provide more context: .
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Does anyone know where the factorial "!" symbol came from?  I can't decide if it is my favorite or least favorite notation in mathematics...
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In group theory it happens very often that you want to say: "The order of $H$ divides / does not divide the order of $G$." But the length of | is then always the same:  $ |H| | |G| $ produces |H|||G|  which is not ideal at all. (The negation \nmid has just this length too.) The length of "divides" should be longer than the "cardinality length". I could use   $ |H| \big| |G|$  but then there is no good way to say "does not divide" with the same length. Also, \big| is no solution when the expression has to be used in subscripts.   I thought it was just me, but I asked other group theorists, and nobody had a solution. I hope there is one.  I am seeking a division sign which is a little longer than the usual | , allows negation (with the same length) and proportionally correct use in subscripts (also under \sum etc.). It does not look professional if the "order sign" has the same length as the "divides" sign. (And what about combinations with absolute values, norms - although personally I don't use them as often as group orders.)
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I have this expression: |x-|x-|x-4||| Now, every | sign has the same size, but I'd like to make the outward pairs bigger.   Is it possible to do it automatically, or do I have to define the size of each | sign manually? It doesn't work with $\left| \right|$. In this case I have 3 abs signs. But what if there would be for example 12? Is it possible to do it automatically?  This works fine:   \[ \abs*{\VPhantomL x-\abs*{\VPhantomM x-\abs{x-4}}} \]     But the inline version doesn't:  $\abs*{\VPhantomL x-\abs*{\VPhantomM x-\abs{x-4}}}$
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My aim is to construct a relational symbol which is graphically equivalent the standard infinity sign (coded by\infty) crossed exactly in the middle of it. Yet I am not able to overcome something. To be more precise:    I would like to have slash sign moved exactly to the middle position of the infinity sign. The above was defined in the following way:  \documentclass{standalone} \begin{document} \newlength{\length} \settowidth{\length}{$\infty$} \newcommand\ninfty{\mathrel{\infty\hspace{-0.5\length/}}}   $\ninfty$ is not what I am aiming at.  \end{document}   So as you can see my idea was to define the length equal to the length of the infinity sign and then place slash sigh it halfway through it. As it can be seen above it was rather please quarter-way (backwards).  Could you please explain what I did wrong and how can I exactly determine the middle point (in terms of width) of a given mathematical glyph? Or a glyph in general?
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What I mean is that $\mathbb{CRZ}$ etc. are used for different classes of numbers, allowing me to do stuff like this:   $$f:\mathbb{R}\to\mathbb{R}$$ $$f:x\mapsto 3x$$  But say I have an expression like this:  $$g:x\mapsto x&gt;4$$  What symbol would you use to represent a boolean result? a $\mathbb B$?
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What does the notation in the red box mean?   $$\Huge e^{\displaystyle \large \sum_{k=0}^n \bbox[2px,border:2px solid red]{\color{black} { {n \choose k}}}~\omega^k}$$
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I've been asked to complete this chart and have never come across this symbol before, nor can I find anything about it on google:    What does the $\bar{y}$ with the line over it represent? And also, does the the t^2 column just mean square all of the time values for each row?
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I found , which explains orthogonal and not orthogonal symbols.  I was able quickly to find the orthogonal symbols as \perp, \upvdash etc., but not able to find a top line which strikes the sign from the top left to bottom right. One idea is to combine to symbols e.g., use one of the aboves and add the line in top of it. However I don't know how to do it.
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I've occasionally seen a negative (when a number is simply negative, not a subtraction), typeset as negative sign that's slightly skinnier and above the centre line of text. Is this proper notation for mathematics and how would one go about typesetting this in LaTeX?   Edit  I believe that calculators were what happened to give me this idea, couldn't find it in any of my math books. Thank you all for the help, it's much appreciated.     Thank you 'Antal S-Z' for the photo link.  However, the question remains, how exactly would I typeset this?
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How to create the following symbol?
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In LaTeX, how would I make a long underscore?  For example,  Name _______  Signature _______
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I am currently using \underline{...} to underline text.  However, I want the underline to be closer to the letters (as of now, there's too much whitespace between the letters and the line).  Is there a simple way to do this?
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$\bigodot=?$ $(\sqrt 2) ^ \sqrt 3 \bigodot  (\sqrt 3) ^ \sqrt 2$  where $\bigodot is either \lt or \gt$   In other words, which one is larger $(\sqrt 2) ^ \sqrt 3$ or $(\sqrt 3) ^ \sqrt 2$? The best I could do was ending up with $\sqrt \frac {3}{ 2} = \frac {\ln 3}{\ln 2}$  side question : is there a symbol like encircled $?$ for when what we are trying to find is the correct order symbol like one of $\lt,\leq,=,\geq , \gt $ ?  Hopefully using just juxtopisition of symbols without resorting to real analysis. is it possible to do with precalculs algebra?
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I'd like to write a majuscule delta-like symbol in LaTeX but I can't find it's syntax anywhere. You can see the symbol on equation (12) of the following paper:  "".
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What does this equation mean? What does the $|$ mean? $446617991732222310 | mn(m^k - n^k)$ Here is the complete question for reference -  What is the smallest positive integer $k$, such that for every ordered pair of integers $(m, n)$, we have $446617991732222310 | mn(m^k - n^k)$?  Please help
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I just went to a site to practise some maths as I am studying some maths on my OU course in computing and IT and I ran into some symbols that I did not understand  The questions were   solve $16+14/2+3\cdot 5-11$ (the point was placed halfway between the top and bottom of the numbers) $(11-5)\cdot (63-59+6)/12$, once again point is halfway between top and bottom   Can someone explain what this means if it is different to a decimal point?  Also this symbol was used in other questions $|$ and I was wondering what this meant as well  In context it was the number $-5$ can be written as and one answer was $|-5|$ and another choice was $-|-4|-1$
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To mean that x is an element of X, we can write x \in X. However, in the standard packages, the membership symbol that results is too big; it draws too much attention to itself. This is especially evident when we're doing set theory and writing sets as lowercase, as in x \in y. Does anyone one how to draw a less attention-seeking membership symbol?