Parameter Definition and 392 Threads

For which values of a,b and c, the next function is continuous and differentiable at x=2 ? \left\{\begin{matrix} 3x-1 & x\leq 2\\ ax^{2}+bx+c & x>2 \end{matrix}\right. 1. b=2-c 2. b=6+2c+2a 3. 7+c-2a 4. b=3-a-(3/4)c I know that f(2)=5, and so is the limit of f when x goes to 2 from the left...

Homework Statement Find \iiint (x^{2n} + y^{2n} + z^{2n})\,dV where the integral is taken over the region of 3D space where x^{2} + y^{2} + z^{2} \leq 1 Homework Equations The Attempt at a Solution I tried doing this in Cartesian coordinates, but the limits of integration got...

Hi All, I'm trying to solve the following derivative with respect to the scalar parameter \sigma $$\frac{\partial}{\partial \sigma} \ln|\Sigma|,$$ where \Sigma = (\sigma^2 \Lambda_K) and \Lambda_K is the following symmetric tridiagonal K \times K matrix $$ \Lambda_{K} = \left(...

When calculating whether Boltzmann, Bose-Einstein, or Fermi Dirac should be used there is an equation for Degeneracy Parameter A which can be initially used. Degeneracy Parameter A = (N/V) (h^2 / 2 TT m k T)^(3/2) What is represented by N and V and k? Is N the Number Density, V Volume and k...

Homework Statement The problem is Q2 in the attached Homework Equations The Attempt at a Solution I am trying to determine the rigion of parameters for each number of crosses,where x and y are the distances of the center of cross from the closest line respectively,and θ is the acute angle.I...

Could you check my solution please? Homework Statement find out for which values of ##\lambda>0## the sequence ##(a_n)## ,defined by ##a_1 = \frac{1}{2}, \quad\quad a_{n+1} = \frac{1}{2} (\lambda +a_n)^2, \quad n\in \mathbb{N^*}## converges. If ##(a_n)## converges, find the limit. The...

Homework Statement Decide the density parameter from the following data: z=0.04, m= 17.38 and σ=0.19 Homework Equations Definition of the density parameter: Where p0 is the current density and pc is the critical density. The Attempt at a Solution I feel like I don't...

in the dimensional regularization of the QED we introduct an arbitrary parameter μ with the dimension of a mass... so there are finite terms that are function of μ... so they are arbitrary? how we can fix this parameter? what is the physical meaning of μ?

Homework Statement The problem is to get the classical turning point as a function of the impact parameter b for the Lennard-Jones potential. Homework Equations The Lennard-Jones potential is given as [itex]V(r)=4\epsilon[(\frac{\sigma}{r})^{12}-(\frac{\sigma}{r})^6][\itex]. The effective...

hello I am jagodzziski from poland i would like to ask u about PSIM software actually I am doing single phase SPWM inveter voutput 12V 50HZ .. may i know what parameter for igbt and may u show me the calcultion tq

I am recently trying to identify system parameters with projection algorithm, but faced a problem, and the dynamic model is the following: \ddot{y}(t)+a\cdot\dot{y}(t)=b\cdot e(t) The true value of a is 2.8, b is 0.1. While inputing volt e(t)=12sin(2\pi t)+5sin(2t), I can get a good...

Homework Statement In class we derived the Schwarzschild interior solution (constant density). Examine the behaviour of non-radial null geodesics in this spacetime.Homework Equations \Phi(r)=ln\left(\frac{3\sqrt{1-\frac{2M}{R}}}{2}-\frac{\sqrt{1-\frac{2Mr^2}{R^3}}}{2}\right)...

I'm looking at using AICc to compare a set of nested models and wondered about the following. First, my the errors in my n data points around the fit are not i.i.d. Gaussian (the data have an artifact that the models will not able to fit easily and the artifact introduces dependencies and a...

Homework Statement Eliminate the parameter to find a Cartesian equation for the curve. X=sin(t), y=csc(x) Homework Equations The Attempt at a Solution Is this correct? X=sin(t) Arcsin(x)=t So y=csc(arcsin(x) Can I simplify it further?

Homework Statement In a HW assignment, I'm given the ODE y' = f(x,y,\epsilon) and that y = \phi(x,\epsilon) is a solution to this equation. I'm then asked, is \phi(x,0) a solution to the equation y' = f(x,y,0) This result is used for the second part of the problem, and in...

From what I think I understand, a variable is something you input into a function and you get a certain value from it whereas a parameter is something that gives you a different function but 'adjusted'...so the constant C the translates a graph of a function up and down would be a parameter...is...

Hi, I am looking for information on how to extract circuit parameters. I have a system, and I can experimentally perform current and voltage measurements. For example, I can measure the voltage response of the system as a function of a given input pulse. In addition, I also have an...

Homework Statement Consider the following linear system of equations: x1+2x3-5x4 = 0 x1 + 4x2 +4x3 – 5x4 = 10 x1 + 2x2 + 3x3 – 5x4 = 5 4x1 + 2x2 + 9x3 – 20x4 = 5 b) Solve the equation system with the Gaussian method. c) The solution set describes a plane. Specify it in the parameter...

Homework Statement Discuss for alpha the convergence of the following improper integral: \displaystyle \int\limits_{0}^{3}{\frac{{{x}^{3\alpha }}}{{{\left( 9-{{x}^{2}} \right)}^{\alpha }}}} Homework Equations The Attempt at a Solution Well, my attempt was to simplify the integral to...

I'm trying to find the determinant of a band diagonal matrix that has a parameter, κ, in some of the entries. Some entries are just numerical ones, others (κ X number), while others are (κ + number). I have been told that they way to solve for κ is to find the determinant of the this matrix and...

This is from Matts Roos' text on cosmology. I don't follow the final step and when he integrates I understand the first part of the left side, and the right side. But I don't see where -a'^2(t0) comes from

Homework Statement Using Friedmann equations find the parameter of deceleration q_0 using relative densities \Omega_M,\ \Omega_R,\ \Omega_\Lambda. Homework Equations Friedmann equations, deceleration parameter: q_0=-\frac{\ddot{a_0}a_0}{\dot{a_0}^2} The Attempt at a Solution So from...

Hi, I am trying to fit sample data to a Johnson SU distribution in S-Plus. It seems not many people use S-Plus, so if you are familiar with R then you could help as well. The code that I have is: f.Jsu.fun.takeslist(x,g,l,r,e) which is a function I have made that calculates the PDF of...

I am currently doing a course on CNC Programming (GCode, MCode and also APT Programming). The course is almost over and we are going to have an Exam at the end. The Exam is mostly writing programs but would also have a few theory questions. One of the questions asked in previous exams has been...

Homework Statement Elimnate the parameter to find a rectangular equation of the curve. x=sin t, y= csc t Homework Equations I believe trignometric identities are relevant to this problem. cscx=1/sinx The Attempt at a Solution csc x =1/ sin x thus y=1/x Is this the answer...

Hi everyone, I've got a one-dimensional non-autonomous ODE of the following form: dy / dx = f(x,y;w) x_{0} = g(w) y_{0} = h(x_{0};w) --- i.e., w is a parameter that influences both the derivative dy/dx along with both coordinates in the initial condition (x_{0},y_{0}). I basically want to...

I would appreciate a little help with a parametric equation please. Example. x = t + 1y = 3t - 2 I want to eliminate t x = t + 1 so I change the sides t = x - 1 I now bring in the second equation y = 3t - 2 = 3(x - 1) - 2 = 3x - 5 y = 3x - 5 The above I have understood, but my next...

Hello! I use the Crank-Nicolson numerical method to calculate temperatures on a metalic plate(aluminium) 10cmx30cm. I assume that the left vertical side is always in 0 degrees Celsious and the right vertical side in 100 degrees.Both horizontal sides are insulated. So we have a heat...

Any problem of collision can be solved using four equations: Conservation of momentum and energy, impulsive forces and impact parameter (distance between center of masses of the particle taken perpendicular to velocity). I can solve problems using first three cases. But how to analyse a problem...

I need to derive the lattice parameter in terms of the Zn-S separation distance, l. I looked up the value and I've found it to be a = \frac{4}{\sqrt{3}}l The way that I started my derivation was saying that each tetrahedron has a sulfide ion in the center, so then we can make a triangle from...

EDIT: Figured it out. Stupid me. I should have solved in terms of x, giving me x=1-(y+3)^2 as my answer. Homework Statement x= 1−t^{2}, y= t−3, −2 ≤ t ≤ 2 Eliminate the parameter to find a Cartesian equation of the curve for −5 ≤ y ≤ −1 Homework Equations N/A The Attempt at a Solution...

Hi, I'm not exactly sure how to solve the following non-homogeneous ODE by variation of parameters. Solve the given non-homogeneous ODE by the variation of parameters: x^2y" + xy' -1/4y = 3/x + 3x Can someone please point me in the right direction? Help will be much appreciated...

My situation is as follows: I have a set of points in a bounded three-dimensional space. Simply put, each point has an X, Y and Z coordinate. I'm looking for a mathematical parameter that (globally) expresses how well the points are distributed over the space. The parameters should take the X...

How do I find the (a,b) parameter space for \begin{align} \dot{x}=& -x+ay+x^2y\\ \dot{y}=& b-ay-x^2y \end{align}

What is a parameter regression in modeling?

Homework Statement The cosmological principle can also be used to derive an expression for the redshift of light (from far away galaxies) in terms of the scale factors at emission and observation. Use the fact that the wavelength in terms of the co-moving coordinates Δx is independent of...

According to Peterdonis in an old thread According to Matterwave in https://www.physicsforums.com/showthread.php?t=573589 msg #11: Peterdonis said Time is a parameter in non-relativistic QM while as a coordinate in relativistic QM/QFT. But Matterwave said parameter and coordinate has...

Greetings everyone , Can anyone point me into the right direction on how to come out with a value/ expression for the density parameter of a radiation dominated universe. Things that I know of/ can recall are: Friedmann equation : 8/3 \pi G ρ R^2 -kc^2 Also when radiation dominates...

Homework Statement A mass of 1000 kg drops from a height of 10.0 m onto a platform of negligible mass. It is desired to design a spring and damper on which to mount the platform so that it will settle to a new equilibrium position 2.00 m below its original position as quickly as possible...

I am solving three non-linear equations in three variables (H0D,H0S and H1S) using FindRoot. In addition to the three variables of interest, there are four parameters in these equations that I would like to be able to vary. My parameters and the range in which I want to vary them are as follows...

Homework Statement a) Eleminate the parameter to find a Cartesian equation of the curve. b) Sketch the curve and indicate with an arrow the direction in which the curve is traced as the parameter increases. Homework Equations x = 2cosh(t) y = 5sinh(t) cosh^2(x) - sinh^2(x) = 1...

A year ago I learned in multi-var calc about curvature, and since then I've wondered something. It came up again today when my dad tried to talk to me about curvature like it was the second derivative. :P Is there a way, or at least any attempt or resource at all, about parameterizing a...

Can someone give me the intuition behind not using time as a parameter for a Cycloid.

What's the order parameter in quasi crystals? Only the broken rotational symmetry?

If Hubble’s constant H0 = da/a does not change in time between two times t0 and t, how does the cosmological scale factor a(t) vary between these times? This is from a past exam paper, and being quite honest I don't even know where to start with it. Any help would be appreciated. So far...

Homework Statement For which parameter \alpha\in\mathbb{R} the function: f(x, y)= \begin{cases}|x|^\alpha \sin(y),&\mbox{ if } x\ne 0;\\ 0, & \mbox{ if } x=0\end{cases} is differentiable at the point (0, 0)? The Attempt at a Solution For α<0, the function is not continue at (0, 0)...

Homework Statement Starting with the equation below, I need to: - Show that there is a range of values for a for which Ωm≈1 - Derive expressions for the values of a at the endpoints of this range. Homework Equations Ωm(a) = Ωm0/[Ωm0+Ωr0/a+Ωv0a3]. (0 signifies present day values, m=matter...

Beginner's Simulink problem: I have made a Simulink model of a motor-reduction gear-conveyor belt system which outputs velocity (v) and acceleration (a) of the conveyor belt. The reduction gear ratio (i) is a value in a Constant block. My next task is to make a simple optimization of the gear...

I am new to lasers. In the expression for q parameter, 1/q = 1/R - j(λ/πw^2) how did we come to know that w(z) is a measure of decrease in field amplitude E with distance? I can't feel it. Does the gaussian beam itself contract to the minimum diameter? Shouldn't a lens be required for this...

"one parameter family of functions" describing the curve Homework Statement Let a cube of unit length be represented by the set of vectors such that three of the cube's sides are aligned with the three orthonormal basis set vectors e1 e2 and e3, and one of the cube vertices lies on the origin...