# Questions tagged [terminology]

Questions on the usage and meaning of words in mathematics, the names for mathematical entities, and other such questions.

6,846 questions
Filter by
Sorted by
Tagged with
0answers
10 views

### Definition of increment

As feedback on a project about stochastic processes, I was asked to give the definition of "Increment". However I can't seem to find a well written definition anywhere. Would the following ...
1answer
29 views

### Understanding the term “double roots” of a quadratic equation [duplicate]

We know that when a quadratic equation $ax^2 + bx + c = 0$ has zero discriminant value, then the quadratic equation has only "one root". But why do some mathematician call it "double ...
2answers
48 views

### Question About the Definition of a Preorder

Given a set $\{a,b,c,d\}$, does the set of relations $\{a\leq b, b\leq c,c\leq d,d\leq a\}$ give rise to a preorder? If so, what does a preorder have to do with the notion of ordering if $a$ can be ...
1answer
53 views

### What is the meaning of this sentence? “The right side of $a\equiv b \pmod c$ is less than or equal to the left side.”

Let us consider a congruence of the form $$a\equiv b \pmod c$$ What is the meaning of the following sentence? $$\text{The right side of the congruence is less than or equal to the left side.}$$ For ...
1answer
15 views

### Name for cuts which result in shapes that are rotatable images of one another

I'm looking for the technical term to describe any line that cuts through a shape such that the two pieces are a rotation of one another. Obviously any line of reflective symmetry fulfils this ...
1answer
18 views

1answer
66 views

### What's the English term for this algebra operation?

I didn't study maths in English so apologies for this trivial question. How do you say in English when you have a formula 3n + 3 and you want someone to convert it ...
0answers
40 views

### Is there an analogue of the word “parity” for infinite/finite?

We say that two integers have the same parity if they are both even or both odd. Is there a word like this but for infinite/finite instead of odd/even? That is, if a quantity $X$ is finite if and only ...
1answer
34 views

### Dominant eigenvalue definition — is this paper wrong?

I have been reading this paper by Neubert et al. (2004) on calculating reactivities of dynamical models. On page 31, equation 11, they define the two matrices: \begin{pmatrix} -1 &...
1answer
46 views

### Does distinct sets mean disjoint sets?

If A and B are two distinct sets, does that mean A and B are disjoint? Or if A is the subset of B, can A and B be two distinct sets? I am confused here that whether distint and disjoint sets mean the ...
1answer
87 views

### In graph theory, is there a term for the value of the difference between indegree and outdegree?

I'm working on a Graph Theory research project, and one of the key components is talking about the indegrees and the outdegrees of a few particular vertices. I need to define a term for the value of ...
1answer
42 views

### What is the name of the functions $V\to V$ which map every 1-dimensional subspace of $V$ to an 1-dimensional subspace of $V$?

Motivation: the permutations of the projective space $P(V)$ can be regarded as the equivalence classes of such functions (two such functions, $f$ and $g$ are regarded to be equivalent if for every 1-...
0answers
40 views

### Why is there no real coefficients in $g(x) = x - i$, yet there is in $f(x) = x^2 + 1$

Currently, I am going through Precalculus: With Limits (Cengage Textbook), and the topic in class is conjugate pairs. The book defines a conjugate pair as this: "Let be a polynomial function ...
1answer
87 views

### In the notation $T\colon\mathbb{R}^{n} \to \mathbb{R}^m$, does $\mathbb{R}^m$ refer to the codomain or the image of $T$?

Question: It is my understanding that the term codomain refers to a set, of which the image is a subset (although, not ...
0answers
30 views

### Need help understanding notation in mathematical optimization equation?

I have been reading the research paper ["Distributed Joint Power, Association and Flight Control for Massive-MIMO self-Organizing Flying Drones"][1](Paper is from IEEE so it might be stuck behind a ...
1answer
46 views

### Is there a single term for the *pair* (domain, codomain) of function $f$, or generally the (source, target) of morphism $f$?

This is just about finding concise terminology. So if $f:A \to B$, is there a single generic name for the pair (A,B)? What about for the pair (domain, image)?
1answer
46 views

### Is softmax “omni-periodic”?

A function is said to be "periodic" if there's a finite $T$ such that $f(t) = f(t \pm T), \forall$. Usually there's either one such $T$, or none at all. How about infinitely many $T$, that ...
1answer
43 views

### Motivation for the integral notation $\int _{I \in \mathbb{I}} D(I)$ for a categorical limit?

What is the motivation for the integral notation $\int _{I \in \mathbb{I}} D(I)$ for a categorical limit, which is otherwise known as $\underset {\mathbb{I} \leftarrow} {lim} \ D$?
1answer
19 views

### Name for nearly linear (line-shaped) subgraph of a graph

Given a graph, it's straightforward to define a "linear" or line-shaped subgraph: a connected subgraph with two ends which are nodes of degree one, and intermediate nodes of degree two. And ...
1answer
33 views

### Non-trivial connected semi-simple compact Lie group

This is a question about some terminology I'm not familiar with and was hoping to clarify. I've seen it written that every "non-trivial connected semi-simple compact Lie group" contains a ...
1answer
46 views

### What is this notion in statistics?

Question and request I'm sure the following idea is known, and must be basic, in statistics. I suspect it's related to the confidence interval (CI). However, CI is a statistical notion notorious of ...
0answers
20 views

### Linear subspace tangent to a manifold

What does it mean for a vector space/linear subspace to be tangent to a manifold (e.g. in $\mathbb{R}^n$ or $\mathbb{C}^n$)? Does it mean that it is contained in the tangent plane to some point? If ...
1answer
37 views

### What is a subinterval?

I got a specific question, and I think I'm forgetting some of my terminology, specifically what a subinterval is. Here is the question 3 engineers work on a cluster which has a daily limit of 2 ...
0answers
35 views

### How to properly read this proposition?

I'm reading this book (OK, Efe A. Real analysis with economic applications. Princeton University Press, 2007.) and in page 143 the author claim this proposition: I don't know how to properly read the ...
1answer
57 views

### Dartboard paradox and understanding independence

By definition, events $A$ and $B$ are independent if $$P(A \cap B) = P(A)\:P(B).$$ Therefore if an event $A$ happens almost never $\left(P(A)=0\right)$ or almost surely $\left(P(A)=1\right)$, then ...
0answers
31 views

### What is the general solution?

More specifically, does the general solution work for all cases? I am currently learning ordinary different equations but am curious about its meaning in general. Thanks!

1
2 3 4 5
ā¦
137