Functions Definition and 1000 Threads

Hi, I am dealing with an equality of the form: f(x)=g(y,z) and I need to compute ##dx##. Is the following relation correct? dx={(\frac{\partial f}{\partial x})}^{-1}( \frac{\partial g}{\partial y}dy + \frac{\partial g}{\partial z}dz ) Thank you in advance.

Determine, with proof, all the real-valued differentiable functions $f$, defined for real $x > 0$, which satisfy $f(x) + f(y) = f(xy)$ for all $x, y > 0$.

I began by creating 2 classes. A book class and a course class that contains any necessary info about the book and course respectively class bookClass{ private: string theISBN; string thebookName; string thebookAuthor; double thebookCost; int...

Homework Statement This isn't really part of my homework, my homework was to draw a pretty graph, but I am curious about some behavior. I was given a picture of a sinusoidal function. I found it was ##2sin(\frac{\pi}{3}t-\frac{\pi}{6}) + 6##. Then I used trig identities to get...

I apologize for the simplicity of the question (NOT homework). This is a statistical question (not necessarily a quantum mechanical one). If I have an initial probability function with an associated expected value and then a second probability function is superimposed on the initial...

HELP! given p(q(x))=2/(5+x) and q(x)=1+x . find a formula for p(x). Someone please help. I don't know how to do this problem .Thanks in advance (PS: would be really helpful if solution is also given)

I am reading "Introduction to Real Analysis" (Fourth Edition) by Robert G Bartle and Donald R Sherbert ... I am focused on Chapter 5: Continuous Functions ... I need help in fully understanding an aspect of the proof of Theorem 5.3.2 ...Theorem 5.3.2 and its proof ... ... reads as follows:In...

!HELP! The Singapore Flyer, until recently the world's largest Ferris wheel, completes one rotation every 32 minutes.1 Measuring 150 m in diameter, the Flyer is set atop a terminal building, with a total height of 165 m from the ground to the top of the wheel. When viewed from Marina Centre, it...

I am reading "Introduction to Real Analysis" (Fourth Edition) b Robert G Bartle and Donald R Sherbert ... I am focused on Chapter 5: Continuous Functions ... I need help in fully understanding an aspect of Example 5.1.6 (h) ...Example 5.1.6 (h) ... ... reads as follows: In the above text from...

I am reading "Introduction to Real Analysis" (Fourth Edition) b Robert G Bartle and Donald R Sherbert ... I am focused on Chapter 4: Limits ... I need help in fully understanding an aspect of the proof of Theorem 4.2.9 ...Theorem 4.2.9 ... ... reads as...

I am reading "Real Analysis: Foundations and Functions of One Variable"by Miklos Laczkovich and Vera Sos ... I need help with an aspect of Example 10.7 (2) ... Example 10.7 (2) reads as follows: In the above text, we read the following: "... ... Since whenever $$\lvert x - 2 \lvert \lt...

Homework Statement A fixed-point of a function f : A → A is a point a ∈ A such that f(a) = a. The diagonal of A × A is the set of all pairs (a, a) in A × A. (a) Show that f : A → A has a fixed-point if and only if the graph of f intersects the diagonal. (b) Prove that every continuous function...

Homework Statement Show that ##e^x = x## does not have any solutions, and show that ##\sec x = e^{-x^2}## has only one solution. Homework EquationsThe Attempt at a Solution Here is my proof of the first proposition: Since ##e^x## is concave up on ##\Bbb{R}##, it must lie above all of its...

$\textsf{A thin rectangular plate, represented by a region $R$ in the xy-plane}\\$ $\textsf{has a density given by the function p(x,y);}\\$ $\textsf{This function gives the area density in units such as $g/cm^2$}\\$ $\textsf{The mass of the plate is $\displaystyle\iint\limits_{R}p(x,y)dA$}\\$...

Homework Statement Question 5 of attached photo Homework Equations (a,b)R(c,d) and (c,d)R (e,f) implies (a,b)R(e,f) The Attempt at a Solution Attached photo[/B]

Does a circular function with complex variable represent a three-dimensional graph? For example cosiz

In my quest to understand the Euler-Lagrange equation, I've realized I have to understand the chain rule first. So, here's the issue: We have g(\epsilon) = f(t) + \epsilon h(t). We have to compute \frac{\partial F(g(\epsilon))}{\partial \epsilon}. This is supposed to be equal to \frac{\partial...

Homework Statement Does the delta-epsilon limit definition in reverse work for describing limits in monotonic functions? By reversed, one means for lim (x -> a) f(x) = L if for each δ there corresponds ε such that 0 < | x-a | < δ whenever | f(x) - L | < ε. Homework EquationsThe Attempt at...

Nearly every analysis reference I come across defines the derivative for functions on an open interval ##f:(a, b) \rightarrow \mathbb{R}##. I understand that, in constructing the definition of ##f## being differentiable on a point ##c##, we of course want it to first be a point it's domain, so...

In other words, if we are told that A and B commute, then does that mean that there exists some other operator X such that A and B can both be written as power series of X? My instinct is yes but I haven't been able to prove it.

Homework Statement Hello I have this circle with the equation : [/B] (x-a)^2+(y-b)^2=r^2 I want to find dy/dx for it 2. Homework Equations (x-a)^2+(y-b)^2=r^2 The Attempt at a Solution I am looking on the internet and it appears that I should use what is called "Implicit differentiation"...

Hello! (Wave) I am looking at the following exercise (pg. 92, ex. 11.1 , book:Gems of Theoretical Computer Science by Uwe Schöning ) : Why can all boolean functions on $n$ variables be computed by a circuit with only 2 levels (a depth 2 circuit) ? What is the size ( number of gates ) of such a...

Homework Statement f(x)=x[ax-x^2]^ (1/2) for a>0 Then,f(x) A)increases on (3a/4 , a) B)decreases on (0, 3a/4) C)both A,B D)None of these Homework Equations differentiation chain rule f(x) is said to be increasing in (a,b) if it's derivative is positive and decreasing if it's derivative is...

Hello, I am learning about smooth analytic functions and smooth nonanalytic functions, and I am wondering the following: Is there a theorem that states that for any real analytic functions f and g and a point a, that if at a f=g and all of their derivatives are equal, that then f=g?

Homework Statement Use definition (1) to determine if the functions ##y_1## and ##y_2## are linearly dependent on the interval (0,1). ##y_1(t)=cos(t)sin(t)## ##y_2(t)=sin(t)## Homework Equations (1) A pair of functions is said to be linearly independent on the interval ##I## if and only if...

Mod note: Because his caps-lock key is stuck, it's OK for this post to be in all caps. FIRSTLY, MY LAPTOP'S CAPS LOCK IS BEHAVING REALLY WEIRD AND I HAVE NO CONTROL ON IT WHATSOEVER. SO SORRY FOR POSTING IN ALL CAPS/ALL SMALL LETTERS I HAVE RECENTLY LEARNED HYPERBOLIC FUNCTIONS. HOWEVER, I AM...

Homework Statement Three periodic currents have the same ##f=100 Hz##. The amplitude of the second current is ##4 A##. and is equal to half of the amplitude of the third current. Effective value of the third current is 5 times that of the first current. At time ##t_1=2ms## third current...

Hello, I have a question which includes several statements, which I need to decide if they are true or false. I am not sure how to do it, if you could give me hints or "leads", it will mostly appreciated. R is a partial order relation on A, a set of functions from [0,1] to [0,infinity) such...

Suppose I have some sort of a filter, whose transfer function is given by H(w), where w is the angular frequency of the input signal in radians per second. I want to know the maximum value of the transfer function. If I solve for the resonant frequency w0, which from my understanding is the...

Hello! I read in my complex analysis book that holomorphic and analytic "do not always mean the same thing", but in the complex plane they do. In which case they don't mean the same thing? More specifically what does holomoprhic function means outside the complex plane (such that you can define...

Homework Statement I need to simplify the following integral $$f(r, \theta, z) =\frac{1}{j\lambda z} e^{jkr^2/2z} \int^{d/2}_0 \int^{2\pi}_0 \exp \left( -\frac{j2\pi r_0 r}{z\lambda} \cos \theta_0 \right) r_0 \ d\theta_0 dr_0 \tag{1}$$ Using the following integrals: $$\int^{2\pi}_0 \cos (z...

Hi. I seem to have forgotten how to implement equality constraints to barrier NLPs and quadratic NLPs. Say for example I have this problem: Max Z = x12 + 2 x22 ST: x12 + x22 ≤ 1 x1+ x2 ≤ 1 The unconstrained problem (quadratic penalty - correct me if I'm wrong) then becomes Z = - x12 - 2 x22...

I am having some trouble solving the problem shown below. Can anyone point me in the right direction? or provide the location of a worked example? The volume V of a cone of height h and base radius r is given by V=1/3 πr^2 h. The rate of change of its volume V due to stress expansions with...

Homework Statement :[/B] Solve for ##x ##: $$ \sin ^{-1} {x} +\sin ^{-1} {(1-x)} =\cos ^{-1} {x} $$ Answer given: ##0## or ##\frac {1}{2}##. Homework Equations :[/B] All relevant formulae on inverse circular functions may be used. The Attempt at a Solution :[/B] Please see the pic below...

Is their any way to add two wave functions like sin or cos in such a way that you could double the frequency or at least increase it?

How do I show that the payoff function πi isn´t continuous? Why do best replies not always exist?

How come a+a- ψn = nψn ? This is eq. 2.65 of Griffith, Introduction to Quantum Mechanics, 2e. I followed the previous operation from the following analysis but I cannot get anywhere with this statement. Kindly help me with it. Thank you for your time.

Homework Statement [/B] In the equation between (3) and (2), why does the author says that ? Isn't the trigonometric identity actually ? 2. Homework Equations The Attempt at a Solution

I've learned that composition of continuous functions is continuous. ##\log x## and ##|x|## are continuous functions, but it seems that ##\log |x|## is not continuous. Is this the case?

Functions are pretty simple things , they just express a relationship between two different quantities How do i express this function in terms of y(x) = something ?

hi, i was thinking that every function that satisfies the conditions $$f(0)=1$$ $$f(n+1)=(n+1)f(n)$$ could be a generalization of the factorial function, and why the gamma function is the only function that complies with this conditions? I mean why don't exist other functions, or functions...

Hello, In C (or C++), a function is a body of instructions. Functions can be classified as functions that 1) receive inputs and produce outputs 2) receive no inputs and produce no outputs 3) receive inputs and produce no outputs 4) receive no inputs and produce outputs For case 1) and 4), the...

Hello everyone. So I have a test coming up and I am struggling with the concept of figure out what the initial phase or angle of a transfer function is. For instance, consider the following transfer function: L(s) = 4/s(.4s+1)(s+2) So the initial angle for L(s) is -90 degrees. Is there a...

Gauge symmetry is not a symmetry. It is a fake, a redundancy introduced by hand to help us keep track of massless particles in quantum field theory. All physical predictions must be gauge-independent...

Hi. I'm trying to prove that [\Omega] = \int dq \int dp \, \rho_{w}(q,p)\,\Omega_{w}(q,p) where \rho_{w}(q,p) = \frac{1}{2\pi\hbar} \int dy \, \langle q-\frac{y}{2}|\rho|q+\frac{y}{2}\rangle\,\exp(i\frac{py}{\hbar}) is the Wigner function, being \rho a density matrix. On the other hand...

Homework Statement I am trying to show that the integrator is unstable by giving examples of bounded inputs which produce unbounded outputs (i.e. a bounded function whose integral is unbounded). Note: The integrator is a system which gives an output equal to the anti-derivative of its input...

Homework Statement [/B] Let X be a random variable with support on the positive integers (1, 2, 3, . . .) and PMF f(x) = C2 ^(-x) . (a) For what value(s) of C is f a valid PMF? (b) Show that the moment generating function of X is m(t) = Ce^t/(2− e^t) , and determine the interval for t for...

I need help in understanding how Jacobian Elliptic Functions are interpreted as inverses of Elliptic Functions. Please reference the wiki page on Jacobian Elliptic functions: https://en.wikipedia.org/wiki/Jacobi_elliptic_functions For example, if $$u=u(φ,m)$$ is defined as $$u(φ,m) =...

Homework Statement Hi, I am trying to understand the attached: I know that if two functions have zeros and poles at the same point and of the same order then they differ only by a multiplicative constant, so that is fine, as both have a double zero at ##z=w_j/2## and a double pole at...

Homework Statement I have that ##(\psi(z)-e_j)^{1/2}=e^{\frac{-n_jz}{2}}\frac{\sigma(z+\frac{w_j}{2})}{\sigma(\frac{w_j}{2})\sigma(z)}## has period ##w_i## if ##i=j## and period ##2w_i## if ##i\neq j## where ##i,j=1,2,3## and ##w_3=w_1+w_2## (*) where ##e_j=\psi(\frac{w_j}{2})## I have...