Parameters Definition and 489 Threads

Homework Statement Given that y=x^2 is a solution to the differential equation: (x^2)y'' + 2xy' - 6y = 0 <--- Eq.(1) find the general solution of the differential equation (x^2)y'' + 2xy' - 6y = 10(x^7) + 15(x^2) <--- Eq.(2) Hence write...

Not sure if this is a diff geom. question or more appropriate for the strings forum or even relativity or cosmology. I'm doing work involved in inflationary models for compact spaces and the two important quantities are the slow roll parameters \epsilon and \eta. Previously I've been using...

I am looking for informations about CoIr alloys. Who can tell me about crystal structure, lattice parameters of CoIr alloy? Please share me some references about this material. Thanks! :!)

There is a famous saying in physics: "With four parameters I can fit an elephant and with five I can make him wiggle his trunk." Firstly, does anyone know who definitely said it? Secondly, what exactly does it mean in Layman's terms? I have a rough idea, which goes as follows...

I was doing some problems on linear dependence and spanning that had parameters and i wasn't sure how to tell if i got the full answers. Here're two of them: Homework Statement Q1: Find all values of m so that the vectors: {(1-m,2,7),(0,-2-m,12),(0,0,-m)} are linearly dependant. Q2...

can anyone tell me what the impact parameter represents in a simple scattering of particles?

How, if you're given a pair of molecules, would you decide which one might have a higher value for a or b? As I understand for instance, a's value will be high if two molecules are attracted to each other and b's value will be high if two molecules strongly repel each other... but how would...

I hope this is a correct section. I have a function that looks like this: y = a1*x1*a2*x2*a3*x3...an*xn All the parameters of the polynom (a1, a2, a3, ... an) are unknown. Is there a way to find them using a small-medium (less than n) set of examples where each example is a set of xs...

Hi i need to use Variation of Parameters to solve this ODE x^2 y'' - 2xy' + 2y = x^(9/2) So far I was thinking to use Euler's Equation and I really don't know if it will work please help me out with a hint. THanks.

i am trying make a function who's integral is equal to 1 from 0 to 1 and goes threw points (0,0) and (1,0) with the minimal arc length, is tehre anyway to do this? i have tried a couple things, which iwll get me xome question, i have made a triangle, and i have made many trapazoids, the...

Hello. I have an electric circuit that's made from conductors, resistors and coils. I needed to find a voltage between two points and I did. Got answer that plot is: I need to find electric circuit parameters like resonance, degression constant and other. My teacher said something about...

Nonhomogenous LODE (Higher Order) - Method of Variation of Parameters x^3y''' + x^2y'' - 2xy' + 2y = x^3log(x) y(1) = \frac{10}{32} y'(1) = -\frac{24}{32} y''(1) = -\frac{11}{16} I know that \inline y = y_h + y_p and that I probably should use the method of variation...

Hello, While reading up some about the Pauli matrices (which the author indexes by \sigma_{00}, \sigma_{01}, \sigma_{10}, \sigma_{11}) I stumbled across an expression for the multiplication rules: \sigma_{ab} \sigma_{a'b'} = i^{\tilde {w} ( a, b ; a', b' ) } \sigma_{a \oplus a', b...

Given that http://forums.cramster.com/Answer-Board/Image/cramster-equation-200641003458632802260985487500893.gif is the complementary function for the differential equation http://forums.cramster.com/Answer-Board/Image/cramster-equation-200641003635632802261951581250765.gif use the variation...

Use the method of variation of parameters to find a particular solution of http://forums.cramster.com/Answer-Board/Image/cramster-equation-2006491914366328020687673812501253.gif ok i know first i do...

I'm not currently in a class, but I'm doing this for fun.. but technically I would still call it coursework, so I'm posting it here.. I'm studying Redheffer/Sokolnikoff's Mathmatics of Modern Engineering.. and I find a problem on page 75, use the method of variation of parameters to find the...

Maybe there's something I'm missing, but I just realized that if we take a certain general ODE such as y''+k^2 y=0 for example, and assume that in a specific case k=0 the solution is vastly different depending on whether k is set to 0 before or after solving the ODE. The general solution to...

Hey, this is a pretty simple induction problem, but I suck at induction and I think I'm missing something really obvious here, though trying to figure it out whilst having a pretty bad cold isn't much of a good idea. The identity \frac{1}{A_1\cdots A_n}=\int_0^1 dx_1\cdots dx_n \delta...

An ionosonde on a satellite orbiting at 1000 km probes the topside of the F2 layer. If the ionosonde transmits radio pulses downwards at 5.6 MHz and 7.1 MHz and receives radio echoes with delay times of 2 msec and 2.667 msec respectively, determine (a) the F2 electron density at an altitude of...

OKay everyone, this is a big f'ing problem (to me anyways) and its only worth 1 point! But I'm doing it anyways. So here was my attempt, everything seems to be working out like it should but look at what u1 came out too, what am i going to do with that mess? Also do u see any mistakes...

Varation of Parameters fun! diff EQ question, where do i go next? This is my first attempt at doing Variation of parameters, didn't go to bad, things cancled out pretty well but now I'm almost done but I'm stuck! The problem says: Find the solution of y''+15y'+56y = 54*e^(-5t), with y(0) = 8...

Equilibrium = homogeneity of the intensive parameters? It is obvious, that if all intensive parameters of an isolated thermodynamic system are homogeneous then the system is in equilibrium. But, what is the situation with the reverse statement? Is it true, that if an isolated thermodynamic...

this just came out http://arxiv.org/abs/astro-ph/0601168 it is an update, as of year-end 2005, of the best estimates of the values of the main cosmological parameters like the Hubble parameter and the dark energy density (or cosm. const.) and the Omega number which is used to indicate how...

hi, can anybody give me any reference material on crabsteering? and the major design parameters involved?

Hi, Still trying to figure out things with signals and systems... It doesn't go as well as I hoped so please help me... I was checking out a computer program which allows you to specify the parameters of any kind of signal going through any kind of system and then provides you with the...

http://img420.imageshack.us/img420/9300/img02643tt.jpg hello this is the problem i am working on. i started out by using the admittance parameter equation i1 = y11*v1 + y12*v2 i2 = y21*v1 + y22*v2 so i1 is 20/50 by ohms law. so i1 = 0.4 so by the first equation i get v2 = 32 V. also...

What physical parameters define colors like the pigment primaries - red, blue and yellow - and their mixtures? How about light primaries?

i'm confused about that method: 1) when proving that method works, why do you have to make u and v satisfy the 2nd condition u`y1+v`y2=0 2) when you're integrating to find yp, why do you leave out the constant that results from the integration?

I know how to solve the following ODE with variation of parameters: y''+4y=4\sec{\left(2t\right)}. Is there any way to solve this with undetermined coefficients? So far I have tried Yp=Acos(2t)+Bsin(2t), but that didn't work. Thanks for the help.

Please Help Pre-Cal ! 1.A rectangle has one vertex on the line y=L-Fx,x>0 , another at the origin, one on the positive x-axis, and one on the positive y-axis. Find the largest area A that can be enclosed by the rectangle. Show all your work and include a sketch with labels of all important...

Why are communication parameters important when a computer uses a modem? Thank you in advance

solve using method of variation of parameters y''-y = 2/(1+e^x) y'' ==> second order

I have been trying to get this for a while and can't figure it out: if a fundamental matrix of the system x' = Ax is X(t) \left(\begin{array}{cc}e^t&0\\0&e^{-t}\end{array}\right) find a particular solution yp(t) of x' = Ax + [e^t, 2]^{transpose} such that yp(0) = 0 So, I got u(t) =...

I need to solve this D.E. x^2y''-xy' + y = x^3 i'm supposed to use the variation of parameters technique. in that technique i need to get a coeffecient of 1 in the first postion of y'' and then sove the homogenous D.E. y''-\frac{y'}{x} +\frac{y}{x^2}=0 the above leads to...

Hello, I'm trying to understand this concept. Jere's the problem I'm doing. I have to find the general solution for: y'' + 36y = -4xsin(6x) So you then solve for your characteristic equation and get lamda = +/- 6 so y1 = e^-6x and y2 = e^6x You get your matrix for w, w1, and w2. w =...

the problem is fin the general solution of the differential eq : y''+y=2sect + 3 (-pi/2 < t < pi/2) using variation of parameters. I just needed a check to make sure my answer was correct. r^2+1 = 0 r= -i r= i y1= cost y2= sint g(t)= 2sect+ 3 y(t) = c1cost + c2sint + Y(t)...

hi, I face the following problem. I need to find the best values of the parameters a,b,c of the complex function f(x)=a+\frac{b-a}{1+j x c} of the real variable x where (j^2=-1) such that f(2 \pi 10^6)=2.33-j 1.165 10^{-3} and f(2 \pi 10^{10})=2.347-j 3.7552 10^{-3}. It seems to be...

Ok everyone I have a task for homework which asks me to: Determine the parameters for a rope suitable for you to use to make a safe 40m jump. At the moment, I'm unsure of the physics behind bungee jumping, but I know the parameters that I'd have to consider would be the length of the rope...

hey, I have a tough time cracking this one The other problem is: Imagine a glass tube with steel rings around it which have a conductancy rho and a half diameter of R. they are spaced with a distance H. inside the glass tube is a much smaller glass tube. Through it you drop a magnet with mass...