Mathematics Stack Exchange
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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Questions about notation

Over the years, I have had many questions I left unanswered regarding notation. Forgive the fact that the points in this list are somewhat unrelated, but I thought it best to group them all in one question: When solving a quadratic equation by…
Luke Collins
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Implication of mathematical notation

I'm a bit confused by the rules of writing in mathematical notation. In general, if I wrote $\forall x \in (0,3)$ Is it implied that the possible values of $x$ are only real numbers, or could the above line allow for x to equal an imaginary number?…
tethernova
  • 959
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How to write "There is v in set W and P, such that v is in set P"?

How to write "There is v in set W and P, such that v is in P"? I thought of the following possibilities: ∃ v ∈ W : ( ∃ P : v ∈ P) or ∃ v ∈ W, P : v ∈ P Is either of these correct? If not, how should I write it?
Eduardo Bezerra
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What does this operator mean?

I came accross this clock: It features only the numbers 1, 2 and 3 in that order to get all of the numbers. However I have absolutely no idea what the notation is for number 5. If anyone cannot see the image it is basically $12_3$. Just to clarify…
TheLethalConstant
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Mathematical representation of if statements

I'm not a mathematician be any mean, and I need to show a piece of pseudo code as an equation. Here's the pseudo code: if m >= t then s = m+d+r+s else s = 5*m+d+r+s end How can I show this in standard mathematical terms? Preferably in…
Lucien S.
  • 217
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Is comma notation rigorous way to list solutions?

If I like to say that the equation is has roots $x=1$ and $x=2$ then is it formally correct to say that $x=1,2$ or should one use the notation $x\in\{1,2\}$?
student
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Notation: $f(A)$ when $f$ is a function $f:A\to B$.

I've seen the following notation with no previous clarification: $f(A)$, when $f$ is a function $f:A\to B$. Am I correct to assume $f(A)$ should be the image of $f$? E: I'd appreciate downvoters would comment their opinions about this question.
YoTengoUnLCD
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A Type of Union I do not understand

I am not able to read this following union. Could someone please help me to understand it? $\bigcup\limits_ {k \geq n}${${x \in X: |f_k(x)-f(x)|\geq q} $ }
MATH
  • 501
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What does $e$ mean in this expression?

I've seen this formula $$1RM = \frac{100 \cdot w}{48.8 + 53.8 \cdot e^{-0.075 \cdot r}}$$ but I don't know what does the $e$ means. The $w$ stands for weight. The $r$ for repetitions but I think the $e$ is from scientific notication but i'm not…
Lothre1
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Why is the 'argument' of a function named as such?

When watching some videos on various bits of mathematics, I observed the word "argument" being used to describe what is in layman's terms 'the inside of the bracket'. I can understand the use of the word 'argument' in the context of complex numbers;…
Trogdor
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Definition of a Set in terms of Other Sets

I have a set $S(k)$ well defined only if $k>0$, and another set $X$ well defined only if a condition $cond$ is satisfied. I want to define $S(k)$ as the union of $S(k-1)$ and $X$ provided that both are well defined. How can I express this ? If I…
user3749
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How to notate a sequence of decimals

I would like to know if there is a mathematically correct way of describing a sequence of decimal points of a given number. e.g. position 35-46 of π
AKroell
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Use of vinculum to indicate a group of variables represents digits of a number

In my country, there's a long-standing tradition of using the vinculum in contexts similar to this: Let $\overline{ab}$ be a two-digit natural number. Show that ... I have only happened once to come across an explanation for this notation in a…
Rokas
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Trouble Understanding Notation in Reinforcement Learning Paper

I'm looking at this (warning: this is a download of a pdf) paper and am having trouble parsing the notation on top of page 11, steps 4.1 and 4.2. $\forall i \leq t \in T$, $\forall$ $x_i$, $a_i$ Update all Q-Values according to their eligibility…
user3704120
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Where can I find the official rule for multi-line expressions?

Consider this simple exercise: $$1+1+11+1+1 = 15\tag{A}$$ But what if it were a very long expression? Let's assume that it is, then $$\begin{equation*} \begin{split} 1+1+\; & \\ 11+1+1 &= 15 \end{split} \end{equation*}\tag{B}$$ would still…
Royi Namir
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