Term Definition and 742 Threads

Hi I've got a question about a term in a formula I've found in Mandl&Shaw's QFT book It's about equation 2.18 on page 31 L(t) = {\sum_i \delta \bf{x}_i {\cal L}_i \ ... Why is there a delta x_i when summing over all lagrangians for getting the lagrange-function for the whole...

It sounds a bit strange in English (although we have the term in Dutch), so I'm not sure whether this is a generally known/used mathematical term: 'primitivable'. If not, it just comes down to find a primitive function F of f, so that F'=f. Specifically, I'm wondering about primitive functions...

In evolution, the definition is something along the lines of: When one individual increases the fitness of another individual either directly or indirectly, at the cost of decreasing its own fitness. (many argue there is no true form of this) By the way, it is not related to symbiosis in...

I said that A\ell=A_{\textrm{new}}\ell\left(1+\frac{x}{100}\right)\implies A_{\textrm{new}}=\frac{A}{1+\frac{x}{100}}. Also, we know that R\propto\frac{\ell}{A}.. Therefore, R_{\textrm{old}}\propto\frac{\ell}{A} R_{\textrm{new}}\propto\frac{\ell\left(1+\frac{x}{100}\right)^{2}}{A}...

Do imaginary numbers ever manifest themselves in the physical world as we know it? And when I say that, i mean do they ever appear in solutions to problems that we know have physical meaning and aren't in the solutions or derivations purely as mathematical shortcuts? Hopefully this question...

Some times it becomes very difficult to differenciate between Circular motion and Rotational motion.Can anyone tell me to understand clearcut diff. between the two?

Can anyone please give me a hint on any of the following Taylor expansions? That would be so helpful! for all three: Find the first non-zero term in the Taylor series about x = 0 problem 1 \frac{1} {sin^2x} - \frac{1} {x^2} everytime I differentiate the result is zero...so that...

Im having trouble finding a general formula for the nth term for the sequence {1, 1/2, -1/6, -7/24, 1/24, 7/48, -19/336, -503/4480, 17257/362880, 12913/145152,...} if one exist so far I am guessing that n! has something to do with it a hint would be super cool!

Did Einstein like the term "Relativity"? I know that Einstein referred to “Relativity” when he wrote or talked about his theories, but is it true that Einstein was not originally fond of the term “Relativity” to describe his theories by that name? I have found in a couple German publications...

Ok I need me some super help. I have a term paper due next monday and things have just been piling on me like there's no tomorrow so I am barely getting a topic as we speak :cry: :cry: :cry: . So I need some suggestions here. I need an important figure to do a report on that was famous or...

Just out of curiosity: What's each term in a product called? ie the product equivalent of a summand? Thanks :smile:

"cyclic functions" may not be the correct term, but I don't know what else to call them. (only have basic high school math training, no calculus) Here's what I'm looking for. Given the following series of functions f(a) = b (step 1) f(b) = c (step 2) f(c) = d (step 3) ...

Typically photon attenuation is determined by the equation I = I_0 \cdot e^{ - (\mu \cdot z)}. The variable mu is the linear attenuation coefficient and z is the distance traveled through the substance of transport. Is it safe to say that I_0 \cdot e^{ - (\mu \cdot z)} is the damping term of...

Show that x \frac{d(\delta (x))}{dx} = -\delta (x) where \delta (x) is a Dirac delta function. My work: Let f(x) be a arbitrary function. Using integration by parts: \int_{-\infty}^{+\infty}f(x)\left (x \frac{d(\delta (x))}{dx}\right)dx = xf(x)\delta (x)\vert _{-\infty}^{+\infty} -...

I was reviewing a basic food science lecture slide and came across the term CHO in the middle of it on slide 26-28. But there is no explanation of what it is (what it stands for). The lecture was a basic introduction on carbohydrates. Anybody know? The information on the slides are below...

What do you think about this term?

I know this is how to differentiate a funtion consisting of two terms: f(x)=xy , f'(x)=x'y+y'x But is this how to differentiate three terms: f(x)=xyz , f'(x)=(x'y+y'x)+(y'z+z'y)+(x'z+z'x) :confused:

hi, first-time user here although this question deals with algebra, I feel that it pertains to matricies and probability more basically, how do i find long term trends of a matrix with algebra? ex. 2 competing soft drink companines cola A, and cola B presently have 1/3 and 2/3 shares...

I forgot a little detail in the integration by parts formula Is it \int u \,dv = uv + or - \int v \,du I don't remember if its plus or minus...

I've got a very tricky question on my hands. A set of integers are grouped as follows (1), (2,3,4), (5,6,7,8,9),..., until the nth bracket. I have found the total integers in the first (n-1) brackets and it is (n-1)^2 . The next part of the question is to show that the first number...

I need help determining the explicit formula and writing the series in sigma notation with a specified lower limit. In both of them, I cannot tell where one term ends and the other begins, or what to do when the sign changes. Series #1 - 2 - 5 - 8 - 11 - 14 - 17 - 20; lower limit = 3...

Is there a term for a function from a set to itself? It would be handy.

I'm trying to get an expression for the nth term in this series: c_1 = 1 c_n = \sum_{k=1}^{n-1} \frac{c_n}{(n-k)!} For example: c_2 = 1/1! = 1 c_3 = 1/2! +1/1! = 3/2 c_4 = 1/3! + 1/2! + 3/(2\cdot 1!) = 13/6 etc. Since the factor in front of each term is different in each...

Does the term "friction" mean (or imply) that there are lateral forces acting between two surfaces? I'm not so much interested in measuring the forces of friction as I am in understanding the meaning of the term. I hope my question is clearly stated. Thanks, Charles

Is there a commonly used single term that describes a star and all of its associated bodies including its planets, asteroids, comets, Kuiper Belt and Oort Cloud? If not, what is the most acceptable and shortest way of describing this structure?

Can some one explain how rainbow are form in term of photon. and also how photon are related into frequency.

Hello. I've been having such a hard time thinking of the general term of this "Sequence". Actually, I'm not even sure if this is a sequence at all, but it looks like it can be simplified into one summation symbol. \frac{-2}{6}, \frac{-20}{120}, \frac{-1080}{5040}, \frac{-140400}{362880}, ...

find the sum of the first 9 terms in the series 9+11+13+15+17+19+... is the 9 t0 or t1? what is the 9th term? ...21+23+25+27 25 or 27??

Thank god! I don't know what happened, it's over already and I feel like I still have to learn everything. With only quantum and calculus exams remaing, I cannot wait until Christmas. Anyway, to make this homework related I was wondering how much time you guys spend on homework. (just...

Please see the attachment Can anyone tell me why the bracketed term = 0 if c does not equal and integer multiple of q/r ... Thanks :(

Who do you think will most likely be the next Republican running for president and why? Who do you think will most likely be the next Democrat running for president and why?

"Review of Cosmic Vision 2015-2025" begins: "The Cosmic Vision workshop at UNESCO on 15-16 September 2004 showed that Europe is richer than ever in ideas for what should be done in space science in the coming years. This workshop brought us a major step forward in developing the vision of the...

I realize that a physics website isn't the most applicable place for asking this question, but there are so many people here with a wide variety of knowledge that I'm hoping maybe someone could lend me some advice. I am going to be writing a term paper for an English Comp. class in a few...

How do you find the 3rd term of the expansion of (2x-y)^5

Don't you think "troll" is such an overused word on the internet? You say something someone doesn't agree with, and they accuse you of being a troll. It's used as an insult. Trolls use the word "troll". I think the person who invented that word should think about the damage he...

In our labs we often need to find the error percent between the expected value and the measured value. So if we expected to get a value of 9.8 m/s2 for g but got 9.9 m/s2 instead, we say that the error was (9.9 - 9.8)/9.8 % = 1.02%. But what happens if we expect a value of 0 for something, and...

using the sin and cos Maclaurin series, validate each of them using at least 3 values for x and determine how many terms are needed to provide reasonable accuracy. Find the General Term (Tn where n = 1, 2, 3, ...) for each expression and show that each correctly generates the terms of the...

Could I have an explanation on the term calculus maths? The exact meaning of this is a bit vague to me and in Norway we do not use this name for this type of math, whatever it is. Thank yous

The first four terms in an arithmetic sequence are x+y, x-y, xy, x/y, in that order. What is the fifth term? Can anyone show me how to do it? O btw, the fifth term is a number, is not a variable Thx

For visual basic I need to write a term paper on any topic in computer science that is in depth enough to last four pages. Any interesting ideas?

is there such a term as centrifugal force? what exactly is it??

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