Questions tagged [applications]
The [application] tag is meant for questions about applications of mathematical concepts and theorems to a more practical use (e.g. real world usage, less-abstract mathematics, etc.)
1,489
questions
2
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Computational framing of topological counterexamples [duplicate]
Bit of a soft question here, but bear with me:
Topology is infamous as a source of weird counterexamples. Pretty much anyone who has been through a traditional introductory topology course can recall ...
0
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0
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68
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Where can I find real life problems for high school students involving solving triangles?
I have been searching for real-life problems or word problems that involve trigonometry to solve triangles, specifically employing the law of sine and cosine, suitable for high school students. The ...
6
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1
answer
89
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Minimize travel time of a group of people with a motorbike
Problem: A group of $n$ people ($n\geq2$) want to travel from A to B but they can only either walk or use a motorbike (fit 2 people) [note that there is exactly $1$ motorbike for them to use]. Given ...
-1
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Can you help me for prove this Elzaki transform? [closed]
a) proof
$$ E[tf'(t)]=v^2 \frac{d}{dv} [\frac{T(v)}{v}-vf(0)]-v[\frac{T(v)}{v}-vf(0)]$$
Using Elzaki transform
$$E[tf'(t)]=v^2 \frac{d}{dv} [E(f'(t))]-vE(f'(t)) $$
using$$ E[f'(t)]=\frac{T(v)}{v}-vf(...
0
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42
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Probability that random variables with multinomial distribution have a common divisor greater than 1
Consider an election in which $k$ candidates compete: Let $N_{i}$ denote the number of votes for candidate $i$ in the election.
How can we reasonably estimate the probability that the number of votes ...
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2
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85
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If $\frac{p}{p+q}$ is a negative real number, what can I deduce about complex $p$ and $q$? [closed]
Let $p, q$ be complex numbers with non-negative real parts and arbitrary imaginary parts. If $\frac{p}{p+q}$ is a negative real number, what can I deduce about $p$ and $q$?
Motivation: This question ...
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1
answer
69
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Critical Simplices of a Discrete Gradient Vector Field
I just started learning about discrete Morse Theory and I got stuck on a corollary that in the book I'm reading is described as simply following from a lemma.
Denote by $P$ an almost linear metric ...
0
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0
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53
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How to formally justify fudge factor in this difference equation solution?
In Exercise $11$ from Section $3.3$ of Differential Equations With Boundary Value Problems by Polking, Boggess, and Arnold, we first develop the difference equation $P[n + 1] = (1 + \frac{I}{m})P[n],\ ...
4
votes
2
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107
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pow and its relative error
Investigating the floating-point implementation of the $\operatorname{pow}(x,b)=x^b$ with $x,b\in\Bbb R$ in some library implementations, I found that some pow ...
2
votes
1
answer
113
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Standard definition of a game in game theory
Sorry for my naive question, but at the moment I can't quite figure it out.
I'm consulting various documents on game theory in order to get the standard definition of what a game (and an associated ...
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3
answers
53
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How to untangle the ODE $\frac{dx}{dt} = c + \frac{px}{l_0 + pt}$? [closed]
In working on this problem, I came up with the following differential equation:
$$
\frac{dx}{dt} = c + \frac{px}{l_0 + pt}
$$
where $x$ is the dependent variable, $t$ the independent, and all others ...
2
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0
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66
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A first course in abstract algebra Fraleigh 8th ed Section 5 Exercise 65
Cracker Barrel Restaurants place a puzzle called “Jump All But One Game” at each table. The puzzle starts with golf tees arranged in a triangle as in Figure 5.29a where the presence of a tee is noted ...
2
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1
answer
69
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Books on the applications of group theory.
Background:
Applications abound!
I am aware of applications of group theory in general:
cryptography.
physics.
chemistry.
virology.
computer science.
anywhere there's symmetry.
Outside those broad ...
0
votes
1
answer
63
views
Maximum and Minimum of a cubic function
Maximum value of function
$y = x^3-5x^2+2$
a) 5
b) $\infty$
c) 2
d) -5
We know to find maximum value of a function we take first derivative of the function and make it zero and get some point. And ...
0
votes
1
answer
34
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Appropriate model to represent negative numbers
Negative numbers can be introduced by means of temperature, but it does not make sense to multiply two negative temperatures. Moreover, it is even objectionable to say 20°C is twice as hot as 10°C. A ...
0
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0
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15
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Software for Exportable NURBS surfaces from Parametric Equations $x=f(u, v), y=f(u, v), z=f(u, v)$ (Must be Suitable for Engineering)
The title pretty much says it all. Is there any software out there that lets you input 3D parametric equations without having to go to the trouble of writing a bunch of code and then lets you export ...
2
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0
answers
48
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How to generalize curvature to n dimensions parameterized by time instead of arc length?
I am a novice in mathematics in general and even more so in differential geometry. Currently, I am looking to generalize the Frenet-Serret formulas to $n$ dimensions. At the moment, I am interested in ...
0
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1
answer
39
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How to solve an ODE where the rate is directly proportional to two amounts?
Two chemicals in solution react together to form a compound: one unit of compound is formed from $a$ units of chemical $A$ and $b$ units of chemical $B$, with $a + b = 1$. Assume the concentration ...
10
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2
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345
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Applications of Linear Programming to pure mathematics
This semester I'm taking a course in Linear Programming. While the topic is very interesting, all the applications I can find about this topic seem to be outside of mathematics. What are some ...
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102
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What is the Equation for the Batista-Costa Minimal Surface?
The Batista-Costa surface is a triply periodic minimal surface. Three photos of part of the same surface are below:
where the first two were taken form the research paper: The New Boundaries of 3D-...
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1
answer
63
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About vector spaces over finite fields [closed]
I've been dabbling with matrix computations in finite fields, and I've stumbled upon a pattern that I can't understand. Perhaps someone here could shed some light on it?
So, here's what's happening: ...
0
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0
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81
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Is torsion of a multivariate curve defined in n-dimensional space?
I understand that torsion is a concept specific to three-dimensional spaces. Despite searching on Google, I've struggled to find how to extend the concept of torsion to an n-dimensional space.
Is it ...
0
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2
answers
44
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Query regarding approach to solve a given differential equation.
There's a equation
$$N(t) = N(t)\frac{P(t,z)}{B}-C\frac{d(P(t,z))}{dz}$$
$$N(t) = A\frac{dP(t,z)}{dt}$$
Constants:
B,
C=3.9878*10⁻⁷,
$A=0.11941$,
Variables:
N(t) is a function of t and is defined at a ...
1
vote
0
answers
34
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In what situations would using means other than arithmetic/geometric/harmonic make sense?
I understand some use cases for arithmetic (standard), geometric (average growth of two successive discrete growth rates), harmonic (average velocity when consecutively traveling the same distance ...
0
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1
answer
44
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What does it mean to divide an area by a distance?
Let's say for example we divide 2m^2 by 1m, the result is 2m. What is the physical interpretation of this? I mean, dividing an area by a distance makes no sense to me.
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40
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Applications of highly oscillatory integrals
I was reading a series of articles on numerical integration of highly oscillatory functions, e.g.,
S. Olver, Numerical approximation of highly oscillatory integrals
S. Xiang, H. Wang, Fast ...
0
votes
1
answer
129
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What are the possible applications in maths and physics of vector fields along smooth maps?
I am currently working on a problem related to singularities of mappings between manifolds with metrics and the interplay of metric singularities with mapping singularities. Given a smooth map $F:M\...
3
votes
1
answer
79
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A real-world example for a centralizer property
Context: I'm re-studying basic group theory and looking for "real-world" examples/puzzles that can be translated into abstract group theoretic statements. By real-world I mean not something ...
1
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0
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79
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Using the trapezoidal rule for the Maxwell-Boltzman function
Background
I approached my physics professor with question 1 from this LibreTexts resource. (at the bottom of the page), to better understand the material via self-study.
Question
Using the Maxwell-...
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0
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30
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Application of threshold functions from random graph theory
I would like to know if anyone knows about some applications/models where those threshold functions from random graph theory, defined by
$$
\lim_{n \to \infty} P(\mathbb{G}_{n,p} \in \mathcal{F}) =
...
28
votes
4
answers
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Consider a man who travelled exactly 2 km in two hours. Is there a one-hour interval when he traveled exactly 1 km?
Question :
Consider a man who travelled exactly 2 km in two hours.
Is there a one-hour interval when he traveled exactly 1 km?
Can we make a mathematical argument?
I have written my attempt in an ...
0
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1
answer
43
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Rate of change of ordinates and abscissae
The question that I am stuck at goes like this:
On the curve $y^3=27x$, the absolute value of rate of change of ordinate is greater than the absolute value of rate of change of abscissa in the ...
22
votes
5
answers
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What do physicists mean when they say something is "not a vector"?
It's common for physicists to say that not every 3-tuple of real numbers is a vector:
“Well, isn’t torque just a vector?” It does turn out to be a vector, but we do not know that right away without ...
5
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4
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386
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Numerically computing eigenvalues -- what is it useful for?
Cross-posted on Scientific Computing Stack Exchange
Are there real-world applications that call specifically for eigenvalues rather than singular values?
Top eigenvalue is useful to establish ...
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0
answers
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How is rate of change dx/dt in ladder problem doesn't match the actual rate of change.
The pictures above describes the question. We have to find the rate of change in x-axis direction.
The answer is derived from implicit differentiation and is $4/3$. The process is: [y(t) gives y-axis ...
0
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1
answer
102
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What is the Divergence of a Spherically Symmetric Vector Fields?
A vector field is spherically symmetric about the origin if, on every sphere centered at the
origin, it has constant magnitude and points either away from or toward the origin. A vector
field that is ...
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0
answers
43
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Formula like Elo rating but for games where the outcome is numeric?
I'm working on a problem that involves ranking based on pairwise comparisons (it's for a scientific problem, not actually for games). My comparisons return a numerical score (in practice roughly ...
4
votes
6
answers
682
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Is $x^3$ really an increasing function for all intervals?
I had an argument with my maths teacher today...
He says, along with another classmate of mine that $x^3$ is increasing for all intervals. I argue that it isn't.
If we look at conditions for ...
4
votes
1
answer
101
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Interpretation and evaluation of tensor operations in Fourier space calculation
I am attempting to implement a model outlined in this paper:
General magnetostatic shape–shape interactions
Background
This model allows the calculation of magnetostatic interaction energies between ...
0
votes
1
answer
170
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Is there a self-correcting iterative method for approximating pi without using transcendental functions?
The Newton-Raphson method is an iterative method for finding a root of a function, and it is self-correcting in the sense that any error in the initial input is reduced with each iteration so that it ...
0
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What are some practical, non set-theoretic applications of the transfinite recursion theorem
I found some applications of the transfinite recursion theorem within set theory. For example, to prove the following theorem:
A set $A$ is infinite if and only if there exists a one-to-one function $...
2
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0
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Applications of group theory/abstract algebra [duplicate]
Before voting down, I would this text to be read.
This is not exactly a question regarding a hint to solve an exercise of a list or an exam, but a question involving the possible utility of which is ...
0
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0
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Probability analysis in passengers taking trains in a FCFS way under capacity constraint
Suppose there are two trains:
Train 1 and Train 2 have different departure times ($t_1$ and $t_2$) and capacities ($c_1$ and $c_2$).
There are two types of passengers, Type 1 with $d_1$ passengers ...
2
votes
1
answer
59
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Book reccomendations on applications of math
I was always fascinated with pure math, but lately I've been increasingly more interested on applications of math (preferably algebra/topology but other fields would be interesting too) in the real ...
0
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0
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46
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What are applications of changing limit and differentiation/integration?
I know the following theorems but don’t know their usefulness.
If a series $\{f_n\}$ of Riemann integrable functions on $[a, b]$ uniformly converges to $f$, $f$ is Riemann integrable and $\lim\limits_{...
3
votes
1
answer
134
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A "perfect" (chess) rating system
Assume we want to have a player rating system with the following conditions:
For simplicity, no draws.
If A wins against B with ratings $a,b$, their new ratings are $a'=f(a,b),b'=g(a,b)$.
Most ...
0
votes
1
answer
97
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Best approximation of ellipse for collision detection.
I'm working on a personal JavaFX project, and I need to check if two sprites overlap. Originally, I modelled them as ellipses. I was then able to then simplify the problem into checking the ...
0
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0
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14
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Help needed Applications Fourier transform on sound wave propagatiom
[This image show an example in a textbook that am having difficulty in understand how they get 2.12.81 and 2.12.82][1]
Kindly help with the value of B
[1]: https://i.sstatic.net/k4HaF.jpg
1
vote
1
answer
90
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The absurdity of $\Gamma(x)$'s minimum, and can it be applied to the factorial?
I know that the Gamma function can be used as a representation of the factorial, but, at the same time, it is an extrapolation of $x!$. The Gamma function is cool and all, but what are its ...
2
votes
0
answers
38
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Number of pulsations given an specific keyboard
I am given a piano that has 88 keys and I am asked to find how many different melodies with 123 pulsations (each pulsation has obviously one key) are there. However, there is a restriction: there has ...