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.)

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How to convert interest rate to discount factor

I'm studying on Kellison's Theory of Interest and I'm stuck on the exercise 20/a of the 1st chapter. If the $i=0.1$ then $d = 0.0901$ $d_5=\frac{A_5-A_4}{A_5}$ when I insert $d$ into this ...
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1answer
387 views

Engineering Application with Integration

I need help for part $(i)$ ... What I think I know so far: $P = dgh = (1000)(9.8)(h)$ Finding $h$: We will choose an arbitrary value '$x$' somewhere between $0$ and $3$. The height of this ...
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1answer
80 views

What are the use cases related to cluster analysis of different distance metrics?

I'm trying to use different distance metrics like Euclidean, Manhattan, cosine, chebyshev among other distance metrics in my k-means algorithm to calculate distances between the data points and the ...
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2answers
747 views

Does the concept of infinity have any practical applications?

I know what you're thinking: "of course it has, for example, it can be used to tell you how many times you can go around a circle". But that isn't really true, now is it? You'd be dead or the world ...
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33answers
8k views

Can you provide me historical examples of pure mathematics becoming “useful”?

I'm trying to think/know about something but I don't know if my basis premise is plausible, here we go. Sometimes when I'm talking with people about pure mathematics, they usually dismiss it because ...
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2answers
306 views

Interpretation of definite integrals [closed]

It is known from the Fundamental Theorem of Calculus that $$\int_a^b f(x)=F(b)-F(a).$$ This has the geometric interpretation of the net area between $f(x)$ and the $x-$axis. I suspect that there are ...
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1answer
452 views

Applications of category theory and topoi/topos theory in reality

I am an amateur mathematician with an interest in the subjects named in the title. I have recently come to understand that my B.A. in math gives me absolutely no qualification at all in the Swedish ...
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0answers
99 views

Positive eigenvalues in differential-algebraic equations not appearing in time-domain simulation

I am solving a system of equations derived from power system applications. It consists of index-1 differential and algebraic equations in the form: $$\dot{x}=f(x,y) \\ 0=g(x,y)$$ To get the ...
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0answers
87 views

Can a matrix based “secret sharing scheme” be applied to image based secret sharing?

I was reading this and was wondering if it can be used to do secret sharing with images. I dont know a lot about image processing, but if the authors have given a scheme for matrices, how can be ...
2
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1answer
122 views

The PDE $u_t = -\Delta^2 u -\Delta u + f$

Does the PDE $u_t = -\Delta^2 u -\Delta u + f$ have a physical use or meaning? I am asking specifically about the the Laplace term after the biLaplace term.. is it unusual or "unnecessary" in some way ...
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0answers
58 views

Applications for the tail bounds for the hypergeometric distribution

I am interested in the applications for the probability tail bounds (non-asymptotic) for the hypergeometric distribution. I would be very appreciative if you can name or link me to some.
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2answers
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Useless math that become useful

I'm writing an article on Lychrel numbers and some people pointed out that this is completely useless. My idea is to amend my article with some theories that seemed useless when they are created but ...
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4answers
1k views

What is the best base to use?

When I typed this question in google I found this link: http://octomatics.org/ Just from the graphic point of view: this system seems to be easier (when he explains that you can overlap the line). He ...
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1answer
28 views

How to limit the upper and lower sizes of these resulting log outputs?

I've got quite a puzzle for ya mathematicians here :) This could go in the regular stackoverflow but since the subject matter of the question is primarily math I figure I'd ask it here. I wasn't ...
3
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1answer
139 views

Applied calculus problem

This has been returned as homework and I have to make corrections. My teacher isn't very helpful and I can't afford a tutor. When satellites circle closely around a planet or moon, the gravitational ...
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3answers
546 views

What are applications of rings & groups?

I am following a course in basic algebra, and we have covered rings & groups in class, but I am having trouble visualising them. Are there applications of group &/or ring theory that can be ...
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2answers
82 views

Need to explain an application of $y' = ky$

I have to write application of the ODE $y' = ky$. i want application or any that explain little bit. Thanks!
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0answers
189 views

(SOLVED) Adjoint of Frechet derivative (involving gradient operator)

I need some help with a problem (a homework/programming exercise) regarding the adjoint operator of the Frechet derivative of an operator. I have the forward operator $ F(a) = L_a ^{-1}f $ where ...
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3answers
594 views

Probability of 15 consecutive green lights

Introduction Upon a trip home, my mother and I were noticing a very peculiar occurrence: Traffic lights were almost continuously green. Indeed, exactly fifteen different traffic lights were green ...
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1answer
152 views

Applications of the Pontryagin product for abelian groups

For an abelian group $G$, one can give an explicit description of the homology ring $H_*(G, k)$ for e.g. $k=\mathbb{Q}, \mathbb{Z}_p$ or in general PIDs $k$ in which every natural number is ...
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1answer
542 views

Combinations for Screen lock For iPhone / Android

I was wondering if there was a general for formula to calculate the combination of the password lock for the current smart phones The following is the condition We must use four nodes or more to ...
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4answers
645 views

How are complex numbers useful to real number mathematics?

Suppose I have only real number problems, where I need to find solutions. By what means could knowledge about complex numbers be useful? Of course, the obviously applications are: contour ...
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3answers
354 views

What are the applications of Differential Geometry in Robotics?

I am taking up a Grad level course on Differential Geometry. Can any one please tell me the immediate applications of Differential Geometry in Robotics ? Thanks
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1answer
270 views

optimal size of conserve/tin cans

Given a volume V for a conserve can, using calculus we find that the dimensions that minimise the surface area (and hence the cost of material) is such that the height is equal to the diameter (hence ...
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5answers
348 views

Is there any abstract theory of electrical networks?

Designing electrical networks is among the highly mathematical engineering disciplines, which uses a vast scope of techniques from Fourier analysis and complex function theory, to logic, combinatorics ...
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1answer
181 views

Derivation of formula for continues annuities

I'm currently working through a book on the Theory of Interest. Currently, I'm looking at continuous annuities, or annuities that are paid continuously. The book gives the following formula, the ...
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1answer
295 views

Usage of finite fields or Galois fields in real world

I'm currently studying the theory of Galois fields. And I have a question, what practical usage of this finite fields? As stated in Wikipedia: Finite fields are important in number theory, ...
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1answer
69 views

Would they have enough for the car?

Gina Wilson and Taylor Baker are roommates employed at Walmart while attending college. Their goal is to buy a car for $\$15,000$ in cash at the end of the year. For that reason, they have put ...
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2answers
175 views

How many shares does she own?

Jasmin Coleman bought 5,000 shares of GE stock. She held them for 6 months. Then Jasmin sold 190 shares on monay, 450 shares on Tuesday and again on Thursday, and 900 shares on friday. The average ...
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2answers
2k views

Point on the left or right side of a plane in 3D space

I have an alpha plane determined by 3 points in space. How can I check if another point in space is on the left side of the plane or on the right side of it? I need a fast solution for plug-in ...
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1answer
406 views

How many feet of rope would be needed to wrap this device?

So here is the problem. My dad designed this umbrella that is to be wrapped with rope. The rope is 1 inch thick, and the umbrella is made of poles that arch away from a center beam extending upward ...
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6answers
1k views

What sorts of problems can fractals solve?

After doing a bit of research on fractals, I was wondering what sort of real-life applications do fractal have and in what way would they be used to help solve a problem. I already know people use ...
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2answers
130 views

An injective map where each value is mapped to many others?

I want "something" ("something" because maybe it is not really a mathematical function, called F in the above image) that can describe what is shown on the image. A given value from a domain Xi can ...
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1answer
369 views

Applications of the fundamental theorems of affine and projective geometry.

The fundamental theorem of affine/projective geometry says that a bijection between two finite dimensional spaces that preserves the relation of collinearity is a (semi-) affine/projective ...
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1answer
83 views

Showing an inequality with interest rates and compounding

Suppose that your grandmother is receiving Social Security at the start of next year and has to choose between two plans for how to receive her payments. Divide each year into $k$ payment periods ($k$ ...
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1answer
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Confused about Effective Rate of Discount- Theory of Interest

I'm currently reading Kellison's book, The Theory of Interest. I've reached the chapter on Effective Rate of Discount and it's somewhat confusing. The book explains it as a loan where interest is paid ...
3
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2answers
501 views

What branch of mathematics is most needed in the industry or how one can make living with mathematics (apart from teaching)?

If you learn carpentry or programming you have the clear options of becoming a carpenter or programmer. But what if you learn mathematics? I know that there are some financial institutions out there, ...
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2answers
334 views

Application of maths in economics

What are the branches of maths where we can see undoubtful connections with economics? Where can we use mathematical methods or models and apply them to analyze economic concepts?
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1answer
211 views

What's the application of Lipschitz smoothness and how to use it?

I learn that the sufficient condition for Lipschitz smoothness is the function $f$ satisfys that: $$ \mid f(x+h)-f(x)-\langle\xi,h\rangle \mid \leq c\parallel h \parallel ^2 $$ where $\xi = f'$ I ...
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3answers
282 views

What is an application of the dual space?

Does somebody know any application of the dual space in physics, chemistry, biology, computer science or economics? (I would like to add that to the german wikipedia article about the dual space.)
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0answers
330 views

What are applications of Lagrange's identity?

I recently proved for homework the following identity on $\mathbb{C}$: if $a_1, \ldots , a_n, b_1, \ldots, b_n\in\mathbb{C}$, then $$ \left|\sum_{i=1}^na_ib_i\right|^2 = ...
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0answers
103 views

application of some inequalities in optimization theory

I am studding the Theory of Optimization. And it turns out that some classical inequalities (especially like Khinchine, or non-commutative Khinchine inequaliry or Kahane's inequality) are 'very key' ...
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0answers
299 views

Torsion in two dimensions?

This question is about the notion of a connection with torsion in differential geometry, i.e., a connection that is not Levi-Civita. (It's not about the torsion of a curve in three dimensions.) ...
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1answer
158 views

Maximal color difference

I have a picture consisting of a two-dimensional array of ordered triples (red, green, blue) of real numbers from 0 to 1. I'm looking for something like a norm on pictures which expresses the range of ...
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1answer
782 views

Quadric surface graphing applet

Does anybody know of any online tool/applet that can be used to graph quadric surfaces? i.e. If I want an elliptic paraboloid, I can click on "elliptic paraboloid" and enter my own specified values ...
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0answers
222 views

Book recommendation on Applied Integer Programming/Combinatorial Optimization/OR

Having some very basic and theoretical knowledge about these topics from my study, I'm looking for a book (or other good sources) that explains the stuff from a practical point of view. On the one ...
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2answers
370 views

Mathematical formula for biological phenomena?

Math is strongly intervened with Physics and Chemistry: it's used for an assortment of calculations and experiments. However, I find that Biology (at least elementary Biology) is severely lacking in ...
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3answers
571 views

Are questions of convergence important in real life?

In the real world, do we ever need to worry about convergence and what not? I am not talking about whether recursive functions and such terminate, but convergence in analysis. It seems like the ...
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4answers
254 views

Mathematics applied to biology

Can anyone suggest reference material on mathematics applied to biology, in particular the study of the behavior of say simple unicellular organisms or cells? Ideally the level of complexity should be ...
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1answer
74 views

Mean of a practical distribution

I have a graph with an asymmetrical distribution (spectral response for some sensor). The graph is plotted as efficiency values versus vavelength. I must determine the median wavelength. Help please, ...