Homework Statement
Let C be a regular curve enclosing the distinct points w1,..., wn and let p(w)= (w-w1)(w-w2)...(w-wn). Suppose that f(w) is analytic in a region that includes C. Show that P(z)= (1/2\pii)∫(f(w)\divp(w))\times((p(w)-p(z)\div(w-z))\timesdw
is a polynomial of degree n-1...
Homework Statement
I got into a disagreement with a fellow student today. He insisted that it's possible to simplify the system on the right as the system on the left. I agree with him that the difference in potential energy (and, therefore, the kinetic energy) is the same but I insist that...
Hello everyone, i am dealing with the code which can help me to solve fluid dynamics problems with using LBM methods. Anyways, since i am beginner on Fortran i couldn't solve the rank mismatch error, i think it is easy one but i just can't fix it, i am waiting for your help. Here is the problem...
Hi
I've seen this a few times, where we say f = f(x, y; t) for example, without a proper definition or any guidelines of usage. In my mind I read this as "f is a function over x and y, but it is also dependent on t although this is usually a fixed parameter", even though we might have some...
Frisbee flight in Matlab, can't run (Input argument "x" is undefined)
I'm trying to use a frisbee flight simulation made by Sarah Hummel, but I'm having a hard time running it in Matlab.
I get the first message when I press run in the program and the one in red when running in the...
It is possible to do this and it is correct:
\log \left[\sqrt{i}\right] = \log\left\{\exp\left[\frac{i}{2}\left(\frac{\pi}{2}+2\pi n\right)\right]\right\} = \frac{i}{2}\left(\frac{\pi}{2} + 2\pi n\right) = i\left(\frac{\pi}{4} + \pi n\right)
But:
\log \left[i^2 \right] =...
I recently received Why Does the World Exist by Jim Holt. I haven't gotten around to reading anything but the first chapter, but the book opens with a rather interesting paragraph:
The book then starts on a completely different note, and from my skimming it doesn't seem to treat this...
\text{I will prove the Argument THM }
\text{If f(z) is a function that is analytic in a closed simple curved }\gamma
\text{ and has M Poles , and N Zeors inside }\gamma
\text{Then : }\frac{1}{2i\pi } \oint_{\gamma}\, \frac{f'(z)}{f(z)}\, dz \,=\, N-M
\text{Assume : }f(z) =...
Hi,
I'm confused about the exact interpretation of Noether's theorem for fields. I find that the statement of the theorem and its proof are not presented in a precise manner in books.
My main question is: what is the precise heuristic argument that leads to Noether's theorem?
The question...
I thought I understood cantors diagonal argument but then I started to rethink it.
Why couldn't i just line up all the decimal numbers with the the odd natural numbers.
Then when we create a new decimal that is on my list I will line it up with an even number because I haven't used any of...
So recently I have gotten in a heated argument with my friend about heating his apartment (no pun intended). Here is the argument:
My EE friend has a theoretical heater which runs on 1000 watts of power. In his apartment he also has another electronic device (ie. a computer, a television...
I came across this argument in the book The Nature of Space and Time, which is based on a series of lectures given by Hawking and Penrose. Although it relates to Penrose's Weyl curvature hypothesis (WCH), it does not depend on it, and that, to me, makes it a lot more interesting, since I...
Hello.
I have a problem with the statement that specific values, like the speed of light, have no meaning because we can change
these values by a change of units.
For measures attached with units the value(number) has no meaning "per se", I'm ok with that. (Unlike pure numbers like
ratios...
Starting with the Robertson-Walker metric
\large ds^2 = -dt^2 + a^2(t) [ \frac{dr^2}{1-kr^2} + r^2(d\theta^2+\sin^2\theta d\phi^2]
Consider a light ray emitted at the Big Bang traveling radially outwards from our position.
Therefore we have:
ds = 0
d\theta = d\phi = 0
Substituting...
Homework Statement
arg \left\{ sin \frac{8∏}{5} + i \left( 1 + cos\frac{8∏}{5}\right) \right\}
Homework Equations
The Attempt at a Solution
2sin \frac{4∏}{5} cos \frac{4∏}{5} + i2cos^{2} \frac{4∏}{5} \left(cos2θ=2cos^{2}θ-1 and sin2θ=2sinθcosθ\right)
After simplification what...
Homework Statement
Could anyone help me please?
I would like to know the proof of the following Laplace transform pair:
Homework Equations
\mathcal{L}_{t \rightarrow s} \left\{ J_0 \left( a\sqrt{t^2-b^2} \right) \right\}=\frac{e^{-b\sqrt{s^2+a^2}}}{\sqrt{s^2+a^2}}
The Attempt at a Solution...
var square = function (x) {
return x * x;
};
var cube = function (x) {
return square * x;
};
This is my shot, its not right. Please indicate or suggest the correct answear. :)
Homework Statement
Let H(ω) be a complex-value function of the real variable ω. For each of the cases below, find |H(ω)| and argH(ω).
a: H(ω)= 1/(1+iω)^10
b: H(ω)=(-2-iω)/(3+iω)^2
Homework Equations
The Attempt at a Solution
Our prof has not taught how to do these types of questions in...
I'm in truble with a partial differential equation. Actually it is a system of PDE but It would be useful to solve at least one of them.
The most easy one is this one
2 \bar{\xi}\left(\bar{s},\bar{t},\bar{u}\right) - 2 \xi\left(s,t,u\right) +...
I am trying to solve:
(x + 1 + f(-x) )(1 - f ' (x) ) = x+1
f(0) = x_0
x in (-1,1)
I approximated it numerically but any analytic method I try fails. Any ideas?
Torque is defined as:
τ = rxF
this means that the farther from the rotation axis of a body a force is applied, the more it will tend to rotate the body.
My question is:
Can anybody give me a simple argument that a force applied farther from the rotation axis should be better at...
Hey, I'm sorry to bother you guys but I got a quick question I was hoping you guys could answer. I was just hoping someone had a definitive explination as to why a $500 audio amplifier that can put out 200 watts per channel will sound exactly the same as a $10,000 amplifier putting out 200 watts...
z is a complex number such that z = \frac{a}{1+i} + \frac{b}{1-3i}
where a and b are real. If arg(z) = -\frac{\pi}{2} and |z|= 4, find the values of a and b.I got as far as
z = (\frac{a}{2} + \frac{b}{10}) + i(\frac{3b}{10} - \frac{a}{2})
by simplifying the original expression. Then I...
hello, I'm trying to write a program with a subroutine that can handle array valued functions of different dimensions, I'm new to fortran 90 so i have some troubles.
Here's what i tried:
program passing
use functions
use sub_mod
implicit none
integer, dimension(2,2):: a2
integer...
Hi, fellow physicists (to be). This is my first post on the forum, so I hope I get it right. If not so, please let me know :)
introduction to the problem
At the moment I am working on my physics bachelor's thesis at the theoretical department of my university (Amsterdam). My thesis focusses...
Either sales or expenses will go up. If sales go up, then the boss will be happy. If expenses go up, then the boss will be unhappy. Therefore, sales and expenses will not both go up.
How would I go about breaking this apart? My attempt goes like this
S- be sales go up
E- expenses go up...
Homework Statement
lim_{x→∞}( \frac{x^x}{(x+1)^x} )^2
2. The attempt at a solution
Well this limit is actually my most recent step to solving this problem. The initial problem was determining whether or not the following infinite series converges:
\sum{(\frac{k}{k+1})^{2k^2}}
The...
Hi all !
I have a derived type as:
TYPE type_atom_type_info
integer:: type_code
character(len=4)::type_cname
real(kind=dbl)::mass
end TYPE type_atom_type_info
I have an array of this type as:
TYPE(type_atom_type_info) atom_type_info(250)
I want to pass this array to a...
I just had arguments with my teacher about my test answer in class. I'm a little upset, but maybe I'm acting like a spoilt brat (I'll be the first to admit it) I went out and I'm using a hallway computer in my college so I can't post images. I still disagree with him-- But I'll try to explain it...
"The precision of the argument function" error message, graph not plotted
I've got a function, integratedadvthirdaltb, that I'm trying to use in plotting some graphs:
thirdaltb[KP_, Ps_, C_, M_] :=
NSolve[Sqrt[2*M]*b +
InverseCDF[NormalDistribution[0, 1], Ps]*...
Homework Statement
37. Let ##z=\frac{i(1+is)}{1-is}## where ##s\epsilon\mathbb{R}##.
(a) Show that
$$\text{Arg}(z)=
\begin{cases}
\quad\frac{\pi}{2}+2\arctan s & \qquad \text{for}\quad s\leq1,\\
-\frac{3\pi}{2}+2\arctan s & \qquad\text{for}\quad s>1.
\end{cases}$$
Homework...
Ok so I am in an argument with my mother about the nature of black holes. She is religious and has classical physics knowledge up to degree level (she has a master's in mechanical engineering) and is very, very stubborn. Ok so she has a theory that physicists have simply arrogantly overlooked...
I'm having a problem with the argument of a subroutine which I didn't write myself, but should be working as intended.
I'm supposed to write my own subroutine named funcs(a,b,c). Then this subroutine that I got has funcs as one of it's arguments subr(a,b,c,funcs,..) and it says in the...
Given the following sequence in the product space R^ω, such that the coordinates of x_n are 1/n,
x1 = {1, 1, 1, ...}
x2 = {1/2, 1/2, 1/2, ...}
x3 = {1/3, 1/3, 1/3, ...}
...
the basis in the box topology can be written as ∏(-1/n, 1/n). However, as n becomes infinitely large, the basis...
I've sometimes seen this argument being used:
The amount of vectors with a given velocity is propotional to the area of the sphere given by:
4πv2, because there are more vectors corresponding to bigger speeds.
But mathematically this is nonsense to me, pretty much like comparing...
Homework Statement
Gamelin VIII.1.6 (8.1.6)
"For a fixed number a, find the number of solutions of
z^5+2z^3-z^2+z=a satisfying Re z > 0"
Homework Equations
The argument principle relating the change in the argument to the number of zeros and poles of the function on the domain.
The...
Homework Statement
Its not really a problem I was just wondering if the argument for any negative real number but no imaginary part was always = to pi?
ie -1, -2,-3, -0.65... is the arg(z)=pi for all these cases
if so I am guessing for positive real numbers with no imaginary part then...
"Foundations" argument: Silberstein et al engage Hiley-channeling-Bohm
Foundations of Physics (ed. 't Hooft) has accepted this Silberstein et al paper for publication.
http://inspirehep.net/record/922919?ln=en which seems to me to resurrect some Bohm trends of thought, perhaps in a new form...
The Kalam cosmological argument as presented by William Lane Craig is as follows:
1. Whatever begins to exist has a cause of its
existence.
2. The universe began to exist.
(semi-intellectual nonsense involving infinity)
3. Therefore, the universe has a cause of its...
This is not a HW question, but a question that I need help solving. I am having an argument with a co-worker about the solution.
There is a 4ft sq sheet of plywood with an 18" wide rubber band stretched across it. To measure the spring constant (stiffness) of the rubber band a 6" diameter...
Hi,
I'm allocating the dimension of some arrays once I have calculated steps, then I send the allocated arrays to a function but I have the error Type/rank mismatch in argument 'a'.
What am I doing wrong?
Cheers
integer i, steps, noutput, savestep
double integrationtime...
Homework Statement
I am going over the first chapter of Velleman's How to Prove It. I have never studied logic before and while I understand most of what is happening, I am not sure that I am understanding how to transform sentences into symbols that can be tested. One of the exercises asks...
Hi guys,
I am going to ask another very stupid question. But surprisingly, I could not find any help on it on internet. My question is:
I have defined a function which doesn't take any any input and one output. When I called it, the program halts. I have checked the function and it is...
My dad has a car lift in his garage with arms that swing out and extend under the car. He says that when you are lowering the lift without a vehicle on it if you stand on the end of the arm then it will apply more downward force causing the lift to lower faster. I think that it doesn't matter...
My wife and I have been debateing this (some would call it an argument) but here goes.
We live in mich and gets real cold here. We have a regular refridgerator that we keep in the garage which is unheated and uninsulated. The debate is if the thermostate in the refridg is set at about 35...