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Mathematics Stack Exchange

Questions tagged [notation]

Questions on the meaning, history, and usage of mathematical symbols and notation. Please remember to mention where (book, paper, webpage, etc.) you encountered any mathematical notation you are asking about.

Before asking a question on the site, please check if you can find your answer in Earliest Uses of Various Mathematical Symbols or the book A History of Mathematical Notations.

Alternatively, a textbook or paper usually takes the time to explain the notation they're using; please remember to mention where you've seen the notation you are asking about.

12848 questions
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What does the expression $A^c$ mean in this context?

In a maths question, I had $A$ with a superscript of $c$, like this: $$A^c$$ What does this mean? In a Venn Diagram $A =$ to 5 and 6.
William
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What does $\min\sum\dots$ indicate?

What does "min" indicate infront of a sigma sign? $$\min \sum_{e\in E} c_e x_e$$ Source: https://www.math.unipd.it/~luigi/courses/metmodoc1718/m08.01.TSPexact.en.pdf
Ryan Cameron
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Notational question regarding repeated composition and multiplication

Assume $A$ to be an operator, $B$ a scalar function - the details should not matter too much here. I know that for an element $c$ the repeated application of the operator can be written as $$ A(A(A(c)))=(A\circ A\circ A)(c)=A^3(c). $$ I am looking…
emma
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What does $\mathbb{R}^E_{\gt 0}$ stand for?

I was studying an article where I encountered $\mathbb{R}^E_{\gt 0}$. I couldn't find out what does this notation mean exactly. I'm sorry if my question is basic, I searched this community but I didn't find the answer to my question. Here is a part…
01000110
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Does the notation $f(x) = \frac{1}{x} \mathbb{1}_{\{ x \neq 0 \}}$ make sense?

I have the function $f : \mathbb{R} \to \mathbb{R}$, $f(x) = \begin{cases} 1/x & (x \neq 0) \\ 0 & (x=0)\end{cases}$ So I would like to denote the function $f$ as more simple, 'one-line' notation, $$ f(x) = \frac{1}{x} \mathbb{1}_{\{ x \neq 0…
Moreblue
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total of non zero value

I want to write a math formula that represents the average of non zero value e.g. if I have 4 numbers, one of them is zero, then the sum of the numbers will be divided by 3. Is it correct to say: $$ \frac {\sum_{k=1}^{4} x_{k}} {|x_{k} > 0|} $$
F A
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Typographic conventions for subscripts?

I was wondering if there were any sort of consistent rules or guidelines for how to properly format subscripts on variables? The primary aims should be to have clear meaning, and consistency with what is mostly used in the literature. A few…
Ulysses
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Is there a notation for polynomial division?

In number theory, for any given integers $a,b$, $a|b$ is defined to mean $a \text{ divides } b$. What about polynomials division? Or any ring? Is $f(X)|g(X)$ generally used to mean $f(X) \text{ divides } g(X)$?
Katlus
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Correstness of the mathematical expression

I have a question regarding some strange mathematical expression defined in the set of positive integers - N : g(N) - greatest power of 2 that divides N. e.g. g(24) = 8 because 8 is divided by 2,4,8 but is not divided by 16 g(0) = ∞ Is point 2.…
aaaa
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What is this codomain?

I was presented with a function $f:X$-->$2^X$ and I'm not sure what is meant by the codomain $2^X$. Any ideas?
user443369
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Sine/Cosine equivalent to Plus or Minus

The job that the $\pm$ symbol does is denoting two expressions that differ only in the sign of the summand following the $\pm$. For example, $$b\pm a$$ denotes both $b+a$ and $b-a$ compactly. I am wondering if a common notation exists for the sine…
Brandon Myers
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notation question on f and f(x)

i have always thought that $f(x)$ denotes a function of $x$ and that $f$ represents this function in a wider sense, as the set of ordered pairs that relate elements between two sets. When my book says suppose $f$ can be differentiated then the…
Carlos Bacca
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Notation for partition of a set induced by a function

For a set $S$ with an equivalence relation $R$, the set of equivalence classes is a partition of $S$ called the "quotient set of $S$ by $R$" and is denoted by $S/R$. Now, let $f$ be a function defined on $S$. Consider the equivalence relation "$f$…
ChargeShivers
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Set notation - problem

I have problem with a notation used in an information theory course. Let $N = \lbrace 1,\dots, n \rbrace$ for $n\in\mathbb{N}$. What does $2^{N}$ mean/denote?
guestfrom
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What's the right notations for the inverse hyperbolic functions? ar_ or arc_?

To notate the inverse hyperbolic functions, we may see two different prefixes: ar_ and arc_. The former stands for AREA, while the latter for ARC. Thus, the latter seems not reasonable, since it is likely to be a sort of false analogy with the…
mengdie1982
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