Term Definition and 775 Threads

Please help what term to use for the following issue. Given a set X = { x1, x2, ..., x_n } and a probability distribution on it P (X) = { p (x1), p (x2), ..., p (x_n) }. Given a division of the set Х on non-overlapping subsets Х1, Х2, ... Х_m, so: X1 U X2 U ... U X_m = X Is there a...

Hey guys, Homework Statement Solve the following DE, y"+t(y')^2=0I'm not sure what to do with the square there. Would it help if i divided the whole equation by y'? Thanks

Homework Statement The question is this: Expressing the kinetic energy in terms of momentum (K=1/2mv2 = p2/2m), prove using symbols, not numbers, that the fractional loss during the collision is equal to M/(m+M) Homework Equations The Attempt at a Solution I'm not sure where to...

I am curious to hear people's opinions and to run a poll on the use of the term electrodynamics vs. the term electromagnetism. Which do you prefer; why? Are there instances where you would use one over the other? Etc? To start off: Some like the use of electromagnetism when speaking of the...

i know that there is a formula to find the nth term. two questions: what does mean for non-integer n (as the recurrence relation breaks down i think), and how was this derived

Im learning math and physics on my own and I have had some problems when it comes to remembering how to do topics about math and physics. Currently I am trying to make more summaries, and a list of math and physics topics in order to remember more about them. Do you guys have any advice or...

I am reading a research paper about "narrow" autocorrelation and at the beginning there is an expression I don't unterstand http://www.wellesley.edu/Physics/brown/pubs/acv85_P1595-P1601.pdf" Does someone know what is meant with the word cross term?

A simple question. Suppose I have \epsilon^2 y''' - y' = \frac{1}{1+x^2}. The goal is to calculate the Fourier transform of y(x,t) where we define, \hat{y}(k,t) = F[\phi] = \int_{-\infty}^{\infty} y e^{ikx} ds We're also given that, F\left[ \frac{1}{1+x^2} \right] = \pi e^{-|k|} Now we...

Hi, Can anyone tell me an algorithm to generate the stationary Gaussian distribution R(t) with \langle R(t) \rangle = 0 (zero mean) \langle R(t) R(t')^{T} \rangle = A \delta(t-t') , A = 2 \gamma k_B T m (autocorrelation) ? What I just wrote is from the Wikipedia article "Langevin...

Homework Statement \int^1_0 \int^1_y sin(x^2) dx dy The Attempt at a Solution This equation cannot be integrated nicely, so I tried to reverse the order of integration: \int^1_0 \int^1_x sin(x^2) dy dx However this only helps for the first step, since when we intregrate by y, we...

Is "black hole" a racially insensitive term? http://blogs.chron.com/sciguy/archives/2008/07/is_black_hole_a.html July 09, 2008 Is "black hole" a racially insensitive term? Apparently to some. From the City Hall Blog at the Dallas Morning News: A special meeting about Dallas County...

Use of the term "pair" vs "ordered pair" Why is it that authors use the term "pair" and "ordered pair" interchangeably and, maybe I'm mistaken, a little imprecisely? For example, in listing the field axioms, the language "for every pair x and y" is usually used. However, surly the author means...

What does it mean when an algebraic variable has a dash above it? _ ---------------------------------------------------------------->z, like that?

I'd like to know how most mathematicians view the concept of set. When used in a context outside of set theory, does the word "set" take a meaning (as opposed to leaving it as an undefined term in a set theory) that does in fact follow the axioms of a complete set theory, and therefore all...

Who coined the term "relativistic mass" I asked this question before and never got an answer. I'm hoping that new people are on here who might just know the answer to the question: Who coined the term "relativistic mass" and where, i.e. I need a reference so I can read the source of the terms...

Hi guys...I am trying the problem 5.2 from Peskin to calculate cross section for Bhabha scattering. In the interference (cross) term, I'm getting a term involving trace of 8 gamma matrices and I am having some trouble in evaluating it. So can anyone help? The term is...

The near identity of Coulomb's law and Newton's law of gravitation is interesting to consider in light of the recent unexpected greater velocity (or acceleration) of deep space probes. If we add a mass term to Coulomb's law and a charge term to Newtons' law, then they are nearly the same...

Homework Statement The nth term for a sequence is the square root of [n/ (n^4 + 1)] Investigate whether it is convergence or divergence. Homework Equations Ratio test and integral test The Attempt at a Solution Ratio test will fail for this question, since no conclusion can be...

For a problem such as \sum (1-3/n)^n with the sum going from 1 to infinity, the textbook shows to use the nth term test & that it diverges. However in a previous chapter the textbook had a theorem that said the limit of \sum (1+x/n)^n will converge to e^x for any number x. So I'm confused...

I'm looking for help with my conceptual understanding of part of the following: 1) If a series is convergent it's nth term approaches 0 as n approaches infinity This makes perfect sense to me. 2) If the nth term of a series does not approach 0 as n approaches infinity, the series is...

Ok i have a few here that i have no idea what to do b]1. Homework Statement [/b] Find the nth term in the series 1/2, 1/3, 2/9, 4/27, 8/81, 16/243 also \Sigma (-1)^n-1/ 5n+1 find the sum Urgent help neededdd ahha.. Thanks

[SOLVED] Double integral with cos(x^n) term Homework Statement Solve the following integral (without using a series development): \displaystyle \int _{0}^{\frac{1}{8}}\int _{\sqrt[3]{y}}^{\frac{1}{2}}\cos\left(20{\pi}x}} ^{4}\right)dx dy Homework Equations N/A The Attempt at a...

Homework Statement I'm working on the last section of the last chapter (11.9 The Higgs Mechanism) of Griffith's book on Elementary Particles. In Problem 11.25 I'm asked to derive the lagrangian that he gets juts after gauging [Eq. 11.131]. That's the one with a Goldstone boson and a strange...

Can someone explain to me why different terms arising from a particular electron configuration have different energies? For example, for carbon in the configuration 1s^22s^22p^2 three terms arise, 3P 1D and 1S. These three terms have different energies but I don't understand why. The electron...

So I got a terrible result in my QM midterm. 17%... Fortunately, its only worth 20% of grade. Thing is I didnt really have time to study for it. I had so much other stuff, and figured Id get a B or C relying on what I learned doing problem sets. Boy was I wrong. I know I can still do...

Well my first semester in university went terribly, I just got by. I really slacked around and wasn't prepared for the workload. I have hopes of going to med school but I'm wondering if a really bad first year will have a big impact on getting in?

i added my question and how i tried to solve it in the link http://img100.imageshack.us/my.php?image=img8257ge1.jpg

I've been wondering about terms you typically find in the action of a field theory, for example consider the kinetic term of a scalar field S=\int d^4x(\partial_\mu\phi\partial^\mu\phi). I've read that it can be thought of as the kinetic energy of the field - but this just doesn't sit to...

is there a technical term for when the mind cannot distinguish between what is real, and what is not. I've read many stories of people doing mental training for basketball, vs those who did know training, and those who did actual physical training, and those who did the mental training, actually...

In some QFT books it is written that the generating functional Z[J]=\int \mathcal{D}\phi e^{i\int d^{4}x(\mathcal{L}_{o} +V(\phi) +J\phi) } can be expressed in equivalent form: Z[J]=e^{i\int d^{4}xV(\phi)} \int \mathcal{D}\phi e^{i\int d^{4}x(\mathcal{L}_{o} +J\phi )}. The only argument...

What does the term "Action" means in physics? What does the term "Action" means in physics?

I am reading the manuals of an electronics measuring instrument, in which the term 'float' is repeated several times. Can anyone explain this term? Thanks in advance.

such as strain gauges/ thermistors etc., which give you a reading of one value (ie strain) after measuring something completely different but related (ie change in electrical resistance)

Can some explain me why first order term in perturbation expansion of scattering matrix gives no contribution for every possible IN and OUT states? It is said that this is connected with the fact that condition of energy-momentum conservation cannot be satisfied for real photons and electrons...

Homework Statement See picture It's (sigma) from k (possibly n?)=1 to +infinity of U_{k} = 2 - (1/n) I'm asked to find: U_{100} limit as k goes to infinity of U_{k} and sigma from k=1 to inf. of U_{k} Homework Equations If I'm not mistaken, 2 - 1/n is the closed for for...

Does anybody know a good topic for a classical mechanics term project. I just don't have any ideas. It can just be a high degree of problem solving for a traditional trivial question or be a Phenomenon.

[SOLVED] Finding the nth term of the maclaurin's expansion of sqrt(1+x) Homework Statement Find the nth term of the Maclaurin's expansion of \sqrt{1+x} Homework Equations The Attempt at a Solution so far I've expanded and gotten...

One of my tasks these days is reseaching about long term reactivity control on a typical PWR. As I know in the long term reactivity control we must consider to the role of burnable absorber and boric acid concentration in reactor core during its operation cycles. So I want to do some...

1. Special Relativity 2. Homework Statement Consider this Lagrangian: L=(1/2) (\partial_{\mu} \Psi)(\partial^{mu} \Psi) + \exp(-(a\times \Psi)^2) Have this field a mass term?Homework Equations The Attempt at a Solution

I am just curious, can frequent masterbation have a permanent reduced sperm count side effect in the long run ?

I know how to write down solutions of wave equation \partial^2_t u(t,x) = \partial^2_x u(t,x) for given initial u(0,x) and \partial_t u(0,x) like this u(t,x) = \frac{1}{2}\Big( u(0,x+t) + u(0,x-t) + \int\limits^{x+t}_{x-t} \partial_t u(0,y) dy\Big), but what about \partial^2_t u(t,x) =...

Hi, folks, Is the exponential (repulsive) term in Born-Mayer potentials supposed to be exp(-r) or exp(1/r)? - r is the interatomic distance; constants ignored I've seen both versions pop up in what appear to be reputable sources. The second one seems to be more popular, but, to me at...

Homework Statement Find an expression for the nth Term: { 1/3, 1, 7/5, 5/3, 13/7 } Homework Equations The Attempt at a Solution The problem has obviously had its fractions reduced on almost every case if not every case. I've been working on this problem for at least 4...

a scientific umbrella term that encompasses everything that has to do with half-breed people, hapas, mixed people, "eurasian" etc.??

How good derivations are there for the viscosity term \nu \nabla^2 u_i, that contributes to the acceleration of fluid, in Navier-Stokes equations? I can see that this term is intuitively reasonable. If I wanted to approximate the velocity of the fluid in an environment of some point...

Write the nth term for the following sequence:

Homework Statement Due to the modification of inner-shell electrons of a multi-electron system, the outer shell electron can feel an effective electrostatic potential as V(r)=-e^2/(4*π*eo*R)-lambda*(e^2/(4*π*eo*R^2)) ; 0<lambda≤1 Find the energy eigenvalues and wavefunctions of the...

In another thread, alec_tronn posted My basic reaction: Write a term paper for a calc 3 class?? My first and continued impression is that this requirement is just shovel work. It hinders rather than aids mathematical education. The time taken to write the paper is time not taken to learn...

What is the light that you are seeing when you look at a crescent moon but you can still see the dark side faintly? thanks

Hi All, I have often heard the term 'non-dimensionalising', and am unsure as to what it really means. I gather that it literally means non dimensionalising the units such that it may be applied to a wider range of situations. My question is, if i have a general linear equation and wish to non...