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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Application of Composition of Functions: Real world examples?

Do you know of a real world example where you'd combine two functions into a composite function? I see this topic in Algebra 2 textbooks, but rarely see actual applications of it. It's usually plug ...
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4answers
282 views

An unexpected application of non-trivial combinatorics

PROBLEM STATEMENT Given two finite sets $A$ and $B$, each containing $s \in \mathbb N$ elements, how many pairs of functions $f \colon A \rightarrow B$ and $g \colon B \rightarrow A$ are there, ...
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1answer
1k views

Real world applications of exponential function; continous case

I am looking for interesting applications in everyday life, technology or science of exponential functions of the type: $$ f\colon \mathbb{R} \to \mathbb{R}, \quad x \mapsto ab^x $$ for the case $a ...
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2answers
42 views

Application of the spectrum of an operator

http://en.wikipedia.org/wiki/Spectrum_of_an_operator What is the application of the spectrum of an operator
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2answers
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How to find (and plot) a probability distribution function?

I'm working on my biometrics course, and I have to plot a pdf (I think it means probability density / distribution function). Here is a sample pdf graph : Introduction to Biometrics page 5 , figure ...
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0answers
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Mathematical analysis of e-shop

I'm ukrainian student, studying applied mathematics in Kiev. I have an online store and some statistics data on it's work. Also I've learned a bit about optimization problems and operation reasearch. ...
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2answers
1k views

Applications of Perfect Numbers

I'm preparing a talk on Mersenne primes, Perfect numbers and Fermat primes. In trying to provide motivation for it all I'd like to provide an application of these things. I came up with these: ...
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2answers
222 views

A model for the spruce budworm population

A model for the spruce budworm population $u(t)$ is governed by $$\frac{du}{dt}=ru\left(1-\frac{u}{q}\right)-\frac{u^2}{1+u^2}$$ where $r,q$ are positive dimensionless parameters. The nonzero stedy ...
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4answers
405 views

Why use differentials to compute error?

I get how to use differentials to compute error, but why is it a "good" method? For example, a standard problem is something like: If the radius of a circle is $3 \pm 0.1$ cm, find the area with ...
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1answer
215 views

Would a risk averse agent ever accept gambles with negative expected value? [closed]

Consider a risk-averse agent (his utility for money is strictly concave) that maximizes expected utility. Would such agent ever a accept a gamble whose expected value is negative? (e.g. think of state ...
4
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1answer
102 views

Who generates the prime numbers for encryption?

I was talking to a friend of mine yesterday about encryption. I was explaining RSA and how prime numbers are used - the product $N = pq$ is known to the public and used to encrypt, but to decrypt you ...
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2answers
200 views

What are the applications of algebraic geometry to electronics?

I am currently pursuing an undergraduate degree in Electronics and Communications Engineering in India. I recently got a research internship to study algebraic geometry for two months at a highly ...
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3answers
128 views

On trusting the mathematical process [closed]

In studying math we are, at least partially, interested in making abstraction of real world problems and solving them through rigorous techniques and methods, and then interpreting the result. Let us ...
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1answer
37 views

Get pair number of given shelf number

I work at a warehouse, and have shelves organized in that way: ...
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1answer
48 views

please help me understand the lecture note? heat equation and fourier series

I don't quite understand equation 3.73 and 3.74. To get $T(x,t)$ I thought I had to multiply F and G. How does that give equation 3.73? I got G as e^{stuff} as in the last bit of equation 3.73. ...
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0answers
29 views

How to find a function that can approximate another blackbox function programmaticly?

This question has been posted on http://stackoverflow.com/questions/21758016/how-to-find-a-function-that-can-approximate-another-blackbox-function-programmat I was suggested to post it here. I ...
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1answer
37 views

Finding the work using integrals

A tank full of water has the shape obtained by revolving the curve $y = arcsin(x)$ around the y axis from $x = 0$ to $x = 1$. Find the work required to pump the water out of the tank. (The density of ...
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6answers
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Applications of Complex Numbers

For my Complex Analysis course, we are to look up applications of Complex Numbers in the real world. The semester has just started and I am still new to the complex field. I want to get a head start ...
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1answer
78 views

Understanding a derivative in a biology article

From this biology article (5th page, right column) They have... $$1-P_t ≈ 1-(1+s)P_{t+1}+\frac{p_{t+1}^2}{2}$$ and they conclude that... $$\frac{dP}{dt} ≈ -sP + \frac{P^2}{2}$$ I don't really ...
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0answers
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Using data points and a best-fit to find a function for quantity with respect to price

So I'm taking an entrepreneurship class, and we're doing a simulation where we run a donut shop. My math is pretty strong (integral and differential calculus level), so I'm trying to use my math ...
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1answer
371 views

convert circuit to nor only gates

for an assignment I need to convert a circuit to NOR gates only circuit. (A+B)C + D I know that morgan's theorem states: (a) (A+B)'=A'B' (b) (AB)'=A'+B' I've seen online how to convert some ...
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1answer
89 views

Applications of the theory of distributions outside of PDEs?

Are there any interesting, important or powerful mathematical applications to the Theory of Distributions besides those dealing with partial differential equations?
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0answers
295 views

Modeling bacterial growth with differential equations

I hope this is the right place for this question. I am working on building a growth model for bacteria for a risk assessment, and would like to move the growth model past static temperature ...
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0answers
129 views

Applications of the Kuratowski closure-complement theorem

I crossed with the Kuratowski closure-complement theorem while learning Munkres's Topology (Problem 21 in Section 17; Page 102, 2nd edition). The following description is from B.J. Gardner and M. ...
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2answers
654 views

differential area

I'm just trying to refresh my calculus a bit, I'm stuck on a question and I'd love some insight. A square measures 0.9cm on each side when drawn with a pencil. When traced over with a marker, it ...
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1answer
246 views

Find the direction of the clock arrow [closed]

A clock is placed such that at 12 noon its small arrow points towards north-east. In which direction does its large arrow point at 1.30 p.m? (A) North (B) South (C) East (D) West (E) None of these
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5answers
431 views

Why - not how - do you solve Differential Equations? [closed]

I know HOW to mechanically solve basic diff. equations. To recap, you start out with the derivative $\frac{dy}{dx}=...$ and you aim to find out y=... To do this, you separate the variables, and ...
2
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1answer
115 views

Does every major genre of mathematics have applications?

I know that it used to be said, in praise by some and as criticism by others, that Number Theory had no applications. Now it is used in cryptography and Quantum Theory. Since the mathematics that ...
2
votes
1answer
935 views

Find derivation (dB/decade) for given amplitude characteristic of low pass filter [Hz, -]

I am trying to find derivation (differential attenuation) for frequency's 600 and 2000 Hz for given amplitude characteristic of low pass filter, which look like this: I assume, that I should ...
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3answers
149 views

red and green apples

We can eat 3 apples per hour. We must eat: 3 green apples once per 2 hours. 4 red apples once per 3 hours. We can't eat fractions of an apple. The apples are named, the 3 green (A, B, C) and the ...
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1answer
6k views

Compound interest formula and continuously compounded interest formula derivation

My textbook gives the formula for compound interest as: $A\left( t\right) =P\left( 1+\dfrac {r}{n}\right) ^{nt}$ Where: P = The principal, r=the annual rate of interest, n= the frequency of ...
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3answers
156 views

Applications of functions of the form $f(x)^{g(x)}$

Early on in my calculus education, I learned how to take the derivative of $x^x$ by re-writing it in the form $e^{x\ln x}$. More generally, this technique is helpful in finding the derivative of ...
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0answers
33 views

integer programming with bounded dimension

We know that integer programming with bounded dimension or fixed number of variables can be solved in polynomial time by Lenstra's result(from results of the LLL algorithm). After heavy foraging i ...
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1answer
607 views

A real life application for QR decomposition

I need to use the QR decomposition of a matrix for a real life application, (use it on a particular matrix form) and I have no idea what to do. Can you suggest me a real life application for this? ...
3
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1answer
64 views

Topic for teaching assessment

I'm in the position to have a teaching assessment with a tutoring agency next week. This assessment will include me teaching the assessor a topic of my choice in 15 minutes, demonstrating the Socratic ...
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1answer
41 views

Calculating an exponentially increasing vector of points in a test and measure system

My application is setting and measuring current and voltage in a physical system with a software algorithm. Given these parameters: min, ...
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0answers
70 views

(Actual) applications of basic differential and integral methods

If this isn't the place, I apologize: At the end of my calculus class, we asked the students (among other things) what some applications of calculus methods are. Disappointingly, many focused on the ...
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0answers
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Showing that pressure reaches its max on the boundary of ideal fluid in a stationary flow

The question is to show that the pressure in the stationary flow of ideal fluid achieves is maximum value on the boundary (and not at an interior point, unless the pressure is constant). I've come up ...
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2answers
116 views

Find the velocity field of ideal fluid that has a sink strength of $2\pi k$ using complex analysis.

The precise question is, find the velocity field of ideal fluid given that the fluid has a sink of strength $2\pi k$ at the origin (and no other singularities) and that it has velocity $V_\infty$ (a ...
4
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1answer
294 views

Background for studying and understanding Stochastic differential equations

Assume I have back ground of the following knowledge based on the textbook as : ODE : ODE by Tenenbaum Baby probability : Ross 's baby probability Baby real anlysis : Bartle's introduction to real ...
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1answer
154 views

Prove or disprove the conjecture about the function below.

After thousands of numerical tests we stated the conjecture that their is exactly one local extremum of the function below. $$ {\rm f}\left(w\right) = {1 \over 2}\sum_{i = 1}^{n}\left({1 \over 1 + ...
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2answers
216 views

What is the simplest mathematical concept that does not map to a physical phenomenon?

One of my colleagues argues that everything in math proves something in the physical world. For instance, he claims that the existence of math to describe fractals proves the infinite divisibility of ...
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0answers
185 views

How is graph theory used to solve problems in number theory?

What are some applications of graph theory in number theory? How can a graph theory approach be useful to solving number theory problems? In general, is graph theory ever useful in making number ...
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1answer
33 views

Extensions to linear control with output constraints

Does anybody know which extensions to the linear controller exist that can cope with constraints in the output value and its derivative? Usually, the plant being controlled have some limits and I ...
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0answers
29 views

basic analytical set of tools — integration, differentiation, convergence and handling of applied maths equations

I am more into mathematical logic, algebra, etc. I am asking for a scrib sheet or short and precise collection of a set of tools which somehow demonstrates the everyday set of tools for integration, ...
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1answer
382 views

Finding the “differentness” of two point clouds

I would like to reduce the "differentness" of two point clouds $X$ and $Y$ to a single comparable value $\lambda$, which would ideally be $0$ when $X$ and $Y$ are identical upto isometry (rotation, ...
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1answer
45 views

Adjust Saturation in CIE L*a*b* space.

Given a color in CIE L*a*b* space, how does one change the saturation? This is what I know... $$\mathrm{chroma} = \sqrt {(a^*)^2 + (b^*)^2}$$ $$\mathrm{hue} = \arctan \left( a^* \over b^* \right)$$ ...
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1answer
233 views

Applications of TQFTs beyond physics

I'm giving a talk at a postgrad seminar on the topic of topological quantum field theories (TQFTs) with a mixed audience of pure and applied mathematicians. As such, I'd like to be able to offer some ...
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1answer
191 views

Application of the weak law of large numbers (Roulette)

I am currently working on the following problem. Imagine the following situation: A player bets 1 dollar, and looses his bet with the probability of 19/37, but is given his bet and an extra dollar ...
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2answers
549 views

Biology: Wright-Fisher model of genetic drift

In evolutionary biology (in population genetics to be more accurate) exists the concept of genetic drift. It describes how an allele (gene variant) (that has no advantage or disadvantage in terms of ...