Functions Definition and 1000 Threads

I understand that Wigner function is a quasi-probability distibution as it can take negative values, but in quantum optics I see that the Q function is mentioned as often. So what is the difference between the Q function and the Wigner Function?

Homework Statement Count the number of surjective functions from {1,2,...,n} to {a,b,c,d}. Use a formula derived from the following four-set venn diagram: Homework Equations None provided. The Attempt at a Solution First, I divided the Venn diagram into sets A,B,C,D and tried to express...

Homework Statement Find area bounded by parabola y^2=2px,p\in\mathbb R and normal to parabola that closes an angle \alpha=\frac{3\pi}{4} with the positive Ox axis. Homework Equations -Area -Integration -Analytic geometry The Attempt at a Solution For p>0 we can find the normal to parabola...

Homework Statement To study the thermodynamic behavior of the limit $$z\rightarrow1$$ it is useful to get the expansions of $$g_{0}\left( z\right),g_{1}\left( z\right),g_{2}\left( z\right)$$ $$\alpha =-\ln z$$ which is small positive number. From, BE integral, $$g_{1}\left( \alpha \right)...

Homework Statement Enter a minimum height and velocity into plot function and return a velocity-height plot. Homework EquationsThe Attempt at a Solution # Find length of general list n = len(K) # Build a list for time [0,20] seconds ( Global) time = n*[0.0] # Acceleration of gravity g =...

Ok, first week of first year of undergraduate physics lab and they explain that we want all our graphs to be linear, and in order to do that we can change our x and y axes to be log(x) or y^2 or whatever. They did some simple examples such as y=(k/x)+c and explained that if the x axes is 1/x we...

I am reading John M. Lee's book: Introduction to Smooth Manifolds ... I am focused on Chapter 3: Tangent Vectors ... I need some help in fully understanding Lee's definition and conversation on pushforwards of $$F$$ at $$p$$ ... ... (see Lee's conversation/discussion posted below ... ... )...

In one of the homework sheets my teacher gave us, we had to calculate area geometrically (meaning no integration was used). Some parts, she said, we needed to just eyeball which I hate doing. In this case the top left portion of a circle described by the equation...

Homework Statement ##A=\{1,2,3,4,5\}##, ##B=\{0,1,2,3,4,5\}##. Find the number of one-one functions ##f:A\rightarrow B## such that ##f(i)\neq i## and ##f(1)\neq 0\text{ or } 1##. Homework Equations Number of derangements of n things =...

Homework Statement How many functions are there from {1,2,3} to {a,b}? Which are injective? Which are surjective? Homework Equations n^m. gives the number of functions The Attempt at a Solution To me the number of functions that can be made are 6 because 3x2=6 but I have read online that n^m...

Hello, Me and my friend were talking about differentiability of some piece-wise functions, but we thought of a problem that we could were not able to come to an agreement on. If the function is: y=sin(x) for x≠0 and y=x^2 for x=0, Is this function differentiable? The graph looks like a normal...

Homework Statement Homework Equations[/B] The Attempt at a Solution From that point, I don't know what to do. How do I prove linear independence if I have no numerical values? Thank you.

Homework Statement ## \phi(k_x) = \begin{cases}\phantom{-} \sqrt{2 \pi},\; \bar{k_x} - \frac{\delta}{2} \le k_x \le \bar{k_x} + \frac{\delta}{2} \\ - \sqrt{2 \pi},\; \bar{k_x} - \delta \le k_x \le \bar{k_x} - \frac{\delta}{2} \:AND \: \bar{k_x} + \frac{\delta}{2} \le k_x \le \bar{k_x} +...

Homework Statement Find the scalar product of diracs delta function ##\delta(\bar{x})## and the bessel function ##J_0## in polar coordinates. I need to do this since I want the orthogonal projection of some function onto the Bessel function and this is a key step towards that solution. I only...

(corrections edited in) 1. Homework Statement Assume ## \psi(x, 0) = e^{-\lambda |x|} \: for \: -\infty < x < +\infty ##. Calculate ## \phi(k_x) ## and show that the widths of ## \phi, \psi ##, reasonably defined, satisfy ##\Delta x \Delta k_x \approx 1 ## Homework Equations ## \phi(k_x) =...

The question is as follows: Suppose you find an implicit solution y(t) to a first order ODE by finding a function H(y, t) such that H(y(t), t) = 0 for all t in the domain. Suppose your friend tries to solve the same ODE and comes up with a different function F(y, t) such that F(y(t), t) = 0 for...

Hi all, just curious. I am just learning about user-defined functions in MSSQL2014. What kind of Math can we do with it? Didn't get much useful from my search.

Hello I'm using the C functions for reading binary files: #include <iostream> #include <stdio.h> void main(){ /*********/ uint32_t head=0; FILE *fin = NULL; fin = fopen("myFile.bin","r"); while(myCondition){ fread(&head,4,1,fin); std::cout << std::hex << head...

I am reading Barrett O'Neil's book: Elementary Differential Geometry ... I need help to get started on Exercise 4(a) of Section 1.1 Euclidean Space ... Exercise 4 of Section 1.1 reads as follows:Can anyone help me to get started on Exercise 4(a) ... I would guess that we need the chain rule...

Homework Statement If d/dx(f(x)) = g(x) and d/dx(g(x)) = f(x2), then d2/dx2(f(x3)) = a) f(x6) b) g(x3) c) 3x2*g(x3) d) 9x4*f(x6) + 6x*g(x3) e) f(x6) + g(x3) Homework EquationsThe Attempt at a Solution The answer is D. Since d/dx(f(x)) = g(x), I said that d/dx(f(x3)) should equal 3x2*g(x3), then...

Consider the map ##\phi (t,s) \mapsto (f(t,s),g(t,s))##, a point belonging to the envelope of this map satisfy the condition ##J_{\phi}(t,s)=0##. What is the role of the Jacobian in maps like these and why points in the envelope have to satisfy ##J_{\phi}(t,s)=0##?

hey so if you are taking a floor function of a fraction >1, is there any way to predict anything about it's factorization? what about when the numerator is a factorial and the denominator is made up of factors that divide said factorial but to larger exponents then those that divide the...

I was not sure where to post this here or in calculus, but seeing as the underlying basic principle of my question is regarding parity of functions I am posting it here, but feel free to move if needed. Basically I am getting ready for a (intro to) QM exam and I still struggle with some basic...

What's $1. ~ \displaystyle \arccos(\cos\frac{4\pi}{3})?$ Is this correct? The range is $[0, \pi]$ so I need to write $\cos\frac{4\pi}{3}$ as $\cos{t}$ where $t$ is in $[0, \pi]$ $\cos(\frac{4\pi}{3}) = \cos(2\pi-\frac{3\pi}{3}) = \cos(\frac{2\pi}{3}) $ so the answer is $\frac{2\pi}{3}$

Hello, I am searching for some kind of transform if it is possible, similar to a Fourier transform, but for an arbitrary function. Sort of an inverse convolution but with a kernel that varies in each point. Or, like I say in the title of this topic a sort of continuous equivalent of fitting a...

Hello Forum, I am trying to get clear on the return statement when defining functions in C. A function is a group of statements that together perform a certain task. A function usually receives some input arguments which it uses to produce some output arguments. In C, we must specify what type...

if we draw a line parallel to the x- axis and passes through a point in the image and the graph intersects at one point is this a one to one function ?

when i was reading a supplementary notes doc from open course ware fro MIT on single variable calculus there was a description about a graphical representation of a single valued function as " if each line parallel to the y- axis and which passes through a point in the domain intersects the...

when i was reading a supplementary notes doc from open course ware fro MIT on single variable calculus there was a description about a graphical representation of a single valued function as " if each line parallel to the y- axis and which passes through a point in the domain intersects the...

Hello people ! Hope you are fine! I tried to find the inner product that u can see below, between two different radial functions. I was expecting to find zero but i found something nonzero. You can see my two questions below in the photo.

I want to show that $$\int_0^{\infty} \frac{ds}{s-q^2} \frac{s^{-1-\epsilon}}{s-t \frac{z}{1-z}} = \Gamma(1-\epsilon) \Gamma(\epsilon) \frac{1}{t \frac{z}{1-z} - q^2} \left((-t)^{-1-\epsilon} \left(\frac{z}{1-z}\right)^{-1-\epsilon} -(-q^2)^{-1-\epsilon}\right) $$ I have many ideas on how to...

Here is a simple question : let f(g(x)) = h(x)*g(x). I want to calculate df/dx. If I use the product rule, I get g(x)h'(x) + h(x)g'x). Now if I use the composition/chain rule, I get df/dx = df/dg * dg/dx = h(x) * g'(x) which is different. I guess my df/dg = h is wrong, but I can't see what...

I figured it out... how do I remove this question?

The following text considers the possible wave functions when the potential is symmetric about ##x=0##. Why must even functions have an even number of nodes? ##y=sin^2x## is even but always have an odd number of nodes in any interval centred about ##x=0##. The part preceding the above text:

I have trouble reconciling orthogonality condition for Wannier functions using both continuous and discrete k-space. I am using the definition of Wannier function and Bloch function as provided by Wikipedia (https://en.wikipedia.org/wiki/Wannier_function). Wannier function: Bloch function: I...

Homework Statement I did not manage to get the final form of the equation. My prefactor in the final form always remain quadratic, whereas the solution shows that it is linear, Homework Equations w refers to wannier function, which relates to the Bloch function ##\mathbf{R}## is this case...

1. Given the function ##xy+cos y+6xy^2=0## , it follows that ## dy/dx=-y/x-siny+12xy##2. My problem is how do we integrate this derivative ## dy/dx=-y/x-siny+12xy## to get back the original function3.## ∫dy/dx dx=y ##

In case of the Green's functions for the Laplace equation, we know that they're all symmetric under the exchange of primed and un-primed variables. But is it generally true for the Green's functions of all differential equations? Thanks

Homework Statement I have run into a number of problems while working through problems regarding Bessel and Modified Bessel Functions. At one point I run into i^{m}e^{\frac{im\pi}{2}} and it needs to equal (-1)^m but I'm not sure how it does. This came up while trying to solve an identity for...

What's the type of wave functions? Is it just: function from a point in spacetime to Z; takes a location and returns an amplitude in discrete units? (bonus question: according to your favorite theory, what is the type of points in spacetime (that is, topology of spacetime)? is it like r^n for...

Hey! :o I am looking at the following: I haven't really understood the proof... Why do we consider the differential equation $y'=P(x)y$ ? (Wondering) Why does the sentence: "If $(3)_{\mathfrak{p}}$ has a solution in $\overline{K}_{\mathfrak{p}}(x)$, then $(3)_{\mathfrak{p}}$...

Consider two functions f, g that take on values at t=0, t=1, t=2. Then the total error between them is: total error = mod(f(0)-g(0)) + mod(f(1)-g(1)) + mod(f(2)-g(2)) where mod is short for module. This seems reasonable enough. Now, consider the two functions to be continuous on [0,2]. What...

Homework Statement [/B] Taken straight out of Szabo and Ostlund's "Quantum Chemistry" problem 2.1: Given a set of K orthonormal spatial functions, \{\psi_{i}^{\alpha}(\mathbf{r})\}, and another set of K orthonormal functions, \{\psi_{i}^{\beta}(\mathbf{r})\}, such that the first set is not...

Homework Statement If M[X(t)] = k (2 + 3e^t)^4 , what is the value of k Homework Equations M[X(t)] = integral ( e^tx * f(x) )dx if X is continuous The Attempt at a Solution I tried differentiating both sides to find f(x), but since it is a definite integral from negative infinity to infinity...

Hello, Im currently in a Calc II class with unfortunately a bad professor (score of 2 on RateMyProfessor), so I often have to resort to outside sources to learn. Our class is currently on Sequences and Series which has been fine up until we hit the topic of relating Power Series and Functions...

Homework Statement There's no reason to give you the problem from scratch. I just want to show that 5 trigonometric functions are linearly independent to prove what the problem wants. These 5 functions are sin2xcos2x. sin2x, cos2x, sin2x and cos2x. Homework Equations...

Homework Statement Sorry for the pictures, I'd normally write out the problem but it is mostly diagrams. Question and work attached. I am looking for help with part (a) right now, the transfer function I obtain is shown at the end of my work. Homework Equations Knowledge of Laplace transforms...

Homework Statement Supposethat X1and X2 are .random variables and that each of them has the uniform distribution on the interval [0, 1]. Find the p.d.f. of Y =X1+X2. Homework Equations Find cdf of Y and then the pdf The Attempt at a Solution the joint pdf would be f(x1,x2)= 1...

If the moment generating function for the random variable X is M[X(t)] = 1/(1+t), what is the third moment of X about the point x = 2? The general formula only states how to find moments about x = 0. Thanks!

Homework Statement If ##f(2x-1)= 6x + 15## and ##g(3x+1)=\frac{2x-1}{3x-5}##, then what is ##f^{-1}\circ g^{-1}(3)## ? a) -2 b) -3 c) -4 d) -5 e) -6 The Attempt at a Solution I think the f inverse and g inverse is ##f^{-1}(6x+15)= 2x-1## ##g^{-1}(\frac{2x-1}{3x-5})=3x+1## and,##f^{-1}\circ...