Variables Definition and 1000 Threads

Suppose you have some partiel DE describing a physical system with 2 degrees of freedom (e.g. the SE). If you try separation of variables you get something like: Hg(x)h(y) = Eg(x)h(y) now you can separate this to two equations, but the energy has to go in one of them. Is the final...

Hi, I'm studying Calculus 2 now, and I am a litle bit confused in this question. 1- Determine and plot the domain of the function of two variables a) f(x,y)=\sqrt[]{1+x^{2}+y^{2}} x^{2}+y^{2}\geq -1 doing x^{2}+y^{2}= -1 i guess this is the graph of Hyperbole, but my teacher said is a...

Author: Saturnino L. Salas, Garret J. Etgen, Einar Hille Title: Calculus: One and Several Variables Amazon link https://www.amazon.com/dp/0471698040/?tag=pfamazon01-20 Prerequisities: High school mathematics Level: Undergrad

I am trying to model the following in a computer simulation: http://webdocs.cs.uAlberta.ca/~sutton/book/ebook/node110.html However I am struggling to understand which variables stand for which. In particular, the variables not defined are: d1 and d2 phi1 and phi2 Another problem...

Homework Statement I am given an integral for which I need to substitute variables to remove a singularity so that the integral can be computed in Matlab using the Composite Trapezoidal Method, and then compared to the integral computed in Maple to 16 digit precision. I am stuck on the variable...

I am having a bit of trouble solving the following system of equations. I know what numbers solve the system, but I can only do so using a computer, such as WolframAlpha. The equations , for those interested, are the four partial derivatives for a Lagrange Multiplier. The four equations are as...

Hello this is my first post here. I found a problem in algebra which i cannot solve and don't even know if there are solutions as asked. It is that one: Homework Statement Find all the integer solutions (x,y) that satisfy the equation:Homework Equations ×3-727× = y3 - 727yThe Attempt at a...

I have a LARGE function that I must integrate over 2 variables, {x,y} both from 0 to 1. The Function looks like : F[x_,y_] = A[q] G[x,y] + B[q] G2[x,y] + (...) Where (...) MAY be 100's of terms long, if not thousands. But the fact is each term is separable, in SOME way to a function of...

Homework Statement Find all solutions. Solve explicitly for y. y^{'}=y^{2}-y Homework Equations The Attempt at a Solution Case where y'=0 0=y(y-1) y=0,1 when y(t)=0 Case where y'\neq0 y'=y^{2}-y \frac{1}{y^{2}-y}y'=1 \int\frac{1}{y^{2}-y}y'dt=∫1dt \int\frac{1}{y^{2}-y}dy=t+c Cant...

The circuit of interest is attached. The question is to solve for I1, I2, I3, I4, and V_diode. My question is will the variables come out to be numbers or dependent on R?This is how I did it and it depends on R: I3=0 b/c of the open. The branch with the open is pretty much not there. Thus, KCL...

Author: James Brown, Ruel Churchill Title: Complex Variables and Applications Amazon link https://www.amazon.com/dp/0073051942/?tag=pfamazon01-20 Table of Contents: Preface Complex Numbers Sums and Products Basic Algebraic Properties Further Properties Vectors and Moduli Complex...

I've read that if one wants to quantize gravity , there must be a smallest length scale " The Planck length " . If I want to measure the position of a point particle then in conventional Quantum mechanics I'll find it at the point $(x,y,z)$ at some-time $t$ with an arbitrary momentum but this...

I'm familiarized with finding limits of most kinds of functions. I was struck by a problem: What if the variables of the function belong to different sets of numbers? My point being, given the function: f(n,q)=\frac{n}{q} With n belonging to the set of natural numbers and q belonging to the...

1.\int { x } dx=x\int { 1 } dx\\ 2.\int { t } dx=t\int { 1 } dx\\ 3.\int _{ x }^{ x+1 }{ x } dt=x\int _{ x }^{ x+1 }{ 1 } dt Which of the equations are correct?

Hi, So I have this simple equation that I'm trying to solve in mathematica , the problem is that although I have all the different values and equation I can't seem to get the solve command to solve it - http://screencast.com/t/a8REzNM0cxSS Any thoughts on what I'm doing wrong? Dave,

Homework Statement A binary information source produces 0 and 1 with equal probability. The output of the source, denoted as X, is transmitted via an additive white Gaussian noise (AWGN) channel. The output of the channel, denoted as Y, satisfies Y = X + N, where the random noise N has the...

Homework Statement Find three numbers x,y,z satisfying the following equations: 9x-6y-10z=1 -6x+4y+7z=0 x2+y2+z2=9 Homework Equations The Attempt at a Solution The book suggests that the best approach is to express 2 unknowns in terms of the third unknown from the first 2...

Homework Statement Find all values of k, if any, that satisfy the equation. [2 2 k]*[1 3 0; 3 0 5; 0 5 -1][2 ; 2 ; k]=0Homework Equations The Attempt at a Solution Multiplying the two matrices on the right [2 2 k] * [8 ; 6 +5k ; 10-k]=0 Multiply again [ 16 + 10+12k + 10k-k^2]=0 I'm...

Hi There, This is my first post in Math, and I can't read a formula beyond arithmetic, so please bear with me. I've always been curious about infinity and how it affects probability. I was reading on Wikipedia about the Infinite Monkey Theorem, and understand (I think) that with a finite...

Homework Statement Okay so I was given this question to start calculating error on other problems. Consider the equation F(x,y,z) = x^4+2y^3+5yz+5. Let the uncertainty in x be represented by the variable dx, the uncertainty in y be represented by the variable dy, and the uncertainty in z...

Homework Statement How can you get m and v^2 in the equation KE=1/2 mv^2? How can you get m,g,h in the equation PE=mgh Homework Equations PE=mgh KE=mv^2

On one side one can define second-order variables as ranging over all elements of Pk(M) for all natural numbers k (P=power set of M, M is the universe of the model, superscript being iteration). On the other side it is sometimes defined as ranging over all first-order relations and predicates...

I'm reading some course notes for a physics class that contain the following step in a derivation: \phi(\vec{x}) = \int \frac{d^3k}{(2\pi)^3}\frac{e^{i\vec{k}\cdot\vec{x}}}{\vec{x}^2 + m^2} Changing to polar coordinates, and writing \vec{k}\cdot\vec{x}=kr \cos\theta, we have: \phi(\vec{x}) =...

i am having a hard time understanding partial derivative for function of dependent variables. for example let's consider $$z=x+y$$ so by usual steps that are mentioned on e.g wikipedia etc. $$\frac{\partial}{\partial x}z=1$$ but what if its also true that $$y=x$$ (or in other words...

[FONT=Times New Roman]I really don't how to start this question. Please help me.

Homework Statement Let f(x,y)=e^{xy} Variables u and v are defined by u=x^{3}-y^{3} , v=x^{2}+xy Find the values of \deltaf/\deltau and \deltaf/\deltav at the point where x=-1 and y=2 Homework Equations N/A The Attempt at a Solution At first I thought that I'd have to write...

Homework Statement Let p(x,y) be a positive polynomial of degree n ,p(x,y)=0 only at the origin.Is it possible that the quotient p(x,y)/[absolute value(x)+absval(y)]^n will have a positive lower bound in the punctured rectangle [-1,1]x[-1,1]-{(0,0)}? Homework Equations The Attempt at a...

[FONT=Courier]Classify the following as discrete or continuous random variables. [FONT=Courier] [FONT=Courier](A) The number of people in India [FONT=Courier](B) The time it takes to overhaul an engine [FONT=Courier](C) The blood pressures of patients admitted to a hospital in one day...

This isn't exactly a homework problem, per se, but this was a district assessment I already took today. I was confident that I would get a good grade, but it turns out I got a measly 65%. I don't remember the exact wording, but I do remember the general idea of it.Homework Statement There are...

Hi Let p(x,y)≥0 be a polynomial of degree n such that p(x,y)=0 only for x=y=0.Does there exist a positive constant C such that the inequality p(x,y)≥C (IxI+IyI)^n (strong inequality!) holds for all -1≤x,y≤1? The simbol I I stands for absolute value.

Hi, Homework Statement I was asked to find the determinant of the following two matrices (please see attachment). Homework Equations The Attempt at a Solution I know that the determinant of the matrix on the left is [(-1)^(n-1)]*(n-1), but I have no idea how to formally derive...

Homework Statement A chemist ran out of a 72 ml solution of 12% alcohol. All that is left in the lab is 8% alcohol and 20% alcohol. How many ml of 8% and 20% would be needed to make a 72 ml solution of 12%? Homework Equations The Attempt at a Solution 8x + 20y = 12

Hi, Homework Statement I was hoping someone could please explain the order of variables in a Jacobian. I mean, once the dependent and independent variables have been identified, how should the Jacobian be formulated. For instance, supposing I have two implicit functions F(x,y,u,v) and...

Homework Statement Prove: f(x,y) = \frac{x(x^{2}-y^{2}}{(x^{2}+y^{2}} if (x,y) \neq (0,0) 0 if (x,y) = (0,0) is continuous at the origin Homework Equations \forall \epsilon > 0 \exists \delta > 0 s.t. if |(x,y)| < \delta then |f(x,y)| < \epsilon (Since we are proving...

I need to drag and drop all the labels into the relevant boxes by the bar chart. Three spaces will be left empty because there is anything to describe them. (See the attachment) I was thinking: title empty empty smalles difference between ... empty independent variable dependent variable...

Homework Statement solve. .2y^3 + .6y^3 - .5y^3 I believe the answer to be .3y^3 Homework Equations The Attempt at a Solution i got the answer to be .8y^3 - .5y^3 = .3y^3 I think this is correct, I'm not sure, please let me know if I finished this correctly.

Homework Statement Let X ~ Exponential(3) and Y ~ Poisson(5). Assume X and Y are independent. Let Z = X + Y. Compute the Cov(X,Z).Homework Equations I know Cov(X, Z) = E(XZ) - E(X)E(Z). But how do I compute E(XZ) and E(Z) ?? Since for E(XZ), I would need the pdf/pmf (Exp is abs cts, while...

X and Y are independent, exponentially distributed random variables - with possibly different parameters Determine the density func. of Z = X / Y How to attack ?

Ok, I think I'm missing some math knowledge and is to why I can't solve this.. or maybe I'm just burnt out for the day.. However here is the situation: Mass = 0.06kg Impact Velocity = 7.34m/s Final Velocity = 0m/s Displacement from impact velocity and final = 0.099m Acceleration = 9.8...

Homework Statement Ʃ(A-i)/(N+1-i) sum of i=1 to N Homework Equations How do I solve this series for all 0<N<A cases. This series is the sum of N geometric variables of changing probability. I'd appreciate any help

Homework Statement Hopefully no one will mind me posting this as an image. But here it is in tex: Using separation of variables, find the function u(x,t), defined for 0\leq x\leq 4\pi and t\geq 0, which satisfies the following conditions: \frac{\partial^2 u}{\partial...

Homework Statement I have four equations and have four variables. I need to solve for each of the variables. I am having difficulty figuring out how to do this. My equations are here. http://imgur.com/EOA8I Homework Equations \frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} = 1 The Attempt...

One of my math teachers discussed stochastic ("random") variables today. In an example, he discussed the probability of picking a random number n, such that n\inℝ, in the interval [0,10]. He proceeded to say that the probability of picking the integer 4 (n = 4) is 0, supporting his claim with...

Homework Statement Homework Equations The Attempt at a Solution I can solve the first part of the question. -2 ≤ k ≤ 2 because -1 ≤ sin(x) ≤ 1. How do I solve the second part of the question? Thanks.

Homework Statement does anyone know how to solve this equation for just x? x + x^2 = a^2*b^2 - 2.01j - j^2 - 15.132 it's possible right? because I'm trying to solve for four variables using four equations but two of my variables will have a first plus a second degree The...

Homework Statement Solve the diffusion equation: u_{xx}-\alpha^2 u_{t}=0 With the boundary and initial conditions: u(0,t)=u_{0} u(L,t)=u_{L} u(x,0=\phi(x) The Attempt at a Solution I want to solve using separation of variables... I start by assuming a solution of the form...

Hi, I am trying to identify the independent and dependent variables in the following experiment: Two groups of patients (Epileptic and Normal) are exposed to varying wavelengths of light and their neural response is quantified and recorded. I am using...

Homework Statement I'm trying to understand how a certain substitution can be made with regards to taking the partial derivative of a function product when the variable I am differentiating by is a function itself.Homework Equations (∂/∂p) (v(p)p(x,t)) = v(p) + (∂v/∂p)pThe Attempt at a...

Homework Statement I must find the oscillations of a circular membrane (drum-like). 1)With the boundary condition that the membrane is fixed at r=a. 2)That the membrane is free. Homework Equations The wave equation \frac{\partial ^2 u }{\partial t^2 } - c^2 \triangle u =0...

This question was asked in my exam and I could not answer it. I would like to know how it can be solved. If $l$ and $m$ are variable real numbers such that $5l^2+6m^2-4lm+3l=0$, then a variable line $lx+my=1$ always touches a fixed parabola, whose axis is parallel to the x-axis. (a) Find the...