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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weird brackets in unit interval

I have found during looking at the book Linear Algebra and its Applications (K. Nordstrom) some weird (for me) notation for belonging to the unit interval, namely, $\lambda \in \ ] 0,1 [$. Does it mean as always that $\lambda$ belongs to $[0,1]$ or…
Yelon
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Avoiding confusion between mixed fractions and multiplication

From a notational standpoint, mixed fractions have a tendency to be confused with multiplication of a number and a fraction, for example $2 \frac{1}{3}=\frac{7}{3}$ vs $2 \frac{1}{3}=\frac{2}{3}$. Of course technically the multiplication should have…
Elliot
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Mathematical notation for length?

I would like to write an equation to sum the values of each number in a vector divided by the length of the vector. What is the proper way to write this formula? As an example, consider vector v: v = [1, 2, 3, 4] 2.5 = 1/4 + 2/4 + 3/4 + 4/4 Is…
user1728853
  • 483
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Math interval notations: Interval raised to a power?

I saw this equation in a paper: $v = (v_{l,0}, v_{r,0}, v_{l,1}, v_{r,1}, v_{l,2}, v_{r,2}, v_{l,3}, v_{r,3}) ∈ [−1, 1]^8 $ What does this interval notation mean?- $[−1, 1]^8$
the_jcv
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What is the arrow pointing to left (←) (but not lim)?

I found the following equation: This is on the explanation of batch normalization on a book titled "Hands-On Machine Learning with Scikit-Learn and TensorFlow", published by O'Reilly. The author writes the following explanation: The algorithm uses…
Blaszard
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What does ∧ mean in an equation?

Note that this is not a caret (^), but rather a ∧. I'm aware it's used as an "and" in logic, but that doesn't seem to fit the context. Here are some examples it's used in.
Kaleb Burnham
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What does the | symbol mean in $3 | n^3 + 5n + 6$?

Using induction prove that: $$3 | n^3 + 5n + 6$$ I don't understand what the "|" symbol means here - the only thing I could find with google was "given", in probability, but I don't think that applies here.
Mark
  • 305
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What is the Correct Math Notation for - "For all $i=1$ to $n$"

I want to make sure I am writing correct math notation... I want to write: "For all $i$ from 1 to $n$" (It's been a while...) How do you write this? I get this so far...$\forall_{i=1,\ \mbox{to}\ n}$ Is this right???
PiE
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What is i (mod p)?

Is there a difference between $i$ mod $p$, and $i$ (mod $p$)? To give context, this is the original problem: if $i \geq 0$ what is $i$ (mod $p$)? edit: Forgot to add the parentheses to example
James
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Is there a definition or standard for the symbol $\pm$

In college, I had been taught the famous formula $$x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}.$$ Here $\pm$ means that I choose either $+$ or $-$. But I have seen sometimes in physics that $\pm$ can mean some interval. If $x=5 \text{ m}\pm 0.05\text{ m}$…
Student
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Should these symbols be italicised?

Differentials should not be italicised according to ISO standards $$ \int f\,dx \Rightarrow \int f\,\mathrm{d}x $$ But should these symbols be italicised? Continuous functions: $C(X,Y)$ vs $\mathrm C(X,Y)$ Imaginary unit: $i$ vs $\mathrm i$ Lp…
Henricus V.
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Scientific Notation Question

I'm taking a practice test on scientific notation. The question is What is .000563x10-7 in proper scientific notation. I chose the answer 5.63x10-3. However, this answer was incorrect and I'm not sure why. Does anyone know what the proper answer…
Dave
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What is the "natural" ($\natural$) symbol?

This paper talks about "$M^\natural$-concave functions". The paper defines what an M$^\natural$-concave function is, but, I would like to know specifically what does the $\natural$ symbol mean? Why is it called "natural" and where else in…
Erel Segal-Halevi
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Difference between | and /

"If we find a prime $p$ such that $p\mid n$ , then $n/p$ is a positive integer that's smaller than $n$." I understand $n/p$ is $n$ divided by $p$ but what is $n\mid p$?
blue-sky
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Element of a sequence notation

I'm writing some equations dealing with sets and sequences. I have a sequence $S$ and want to show that $x$ is an element of $S$, however I am hesitant writing $x \in S$ because I don't want to indicate $S$ is a set. I would also prefer not to…
Thomas
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