Variation Definition and 540 Threads

  1. K

    Nonhomogenous LODE (Method of Variation of Parameters)

    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...
  2. W

    #2 Variation of parameters with complemetry EQ (Diffy Q)

    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...
  3. W

    Variation of Parameters Differential Eq.

    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...
  4. V

    Can someone please explain the cp variation?

    i've read in a website that cp variation is the possible reason for excess matter left over in the big bang, is that true can someone please explain the cp variation?? thanks
  5. S

    Vernal Equinox: Understanding the Yearly Variation

    Today, March 20, "is the Vernal Equinox". This event seems to vary yearly between the 20th and the 22d of March, without any obvious pattern. And I wonder if there is any clear description of the relevant variables that cause the variation. I am not iterested in a formula to calculate it...
  6. H

    Can Variation of Parameters Solve This First-Order Differential Equation?

    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...
  7. H

    Control engineering - load variation

    Hi all! I started my first control engineering course this semester. There are some terms that confused me. I am now learning closed-loop systems. And the lecturer was discussing the reduced sensiticity to process disturbance and load variation of a closed-loop system when compared to a...
  8. M

    Variation of parameters problem, very BIG, but i think i'm right so far Diff EQ

    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...
  9. D

    A variation on the twin paradox

    OK, so I'm pretty familliar with the regular twin paradox and the explinations of how you decide which twin is younger by noticing which one accelerated, and the geometrical view of this using k-calculus and minkowsky diagrams, etc. I just thought of something though, and I guess my relativity...
  10. D

    Magnetic field variation with distance

    First of all I have put in ALOT of research into this and I do realize there is no standard formula for the variation of B with the distance because the configuration/polarities and so on tend to get complicated. However, part of my investigation involves measuring the variation of the...
  11. V

    Time variation in the event horizon

    i haven't yet got this concept. i have read about the time "freezing" near a BH , but am not clear. can u please explain what actually happens? why does the time stop? i also want to know one thing-- when, supposing 'A' enters the event horizon he moves slowly towards the singularity because of...
  12. A

    What Is the Variation of the Action?

    I don't have access to textbooks. The internet at present is pretty much my only source of information. I tried looking on the net but couldn't find anything pertaining to my questions. Ok so I have the expression for a Poincare invariant action. Then I have to find the variation of the...
  13. A

    Understanding the Variation of Poincaré Invariant Action

    If I have the expression for a Poincaré invariant action, how do I find the variation of the action? Any help/hints much appreciated, thanks ;)
  14. A

    Solution by variation of parameters

    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?
  15. A

    Undetermined Coefficients / Variation of Parameters

    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.
  16. D

    Can Proportional Variation be Deduced Algebraically from Given Equations?

    Consider the following situation : There are three variables A, B and C. (and i,j,k are constants ) Keeping C constant, and varying the other two, you find that A = kB ------(1) Now, Keeping B constant, and varying the other two...
  17. C

    Functional variation of Lagrangian densities

    Why do we treat a scalar field phi and its derivatives as being independent when trying to find a stationary solution for the action? Doesn't that give too general solutions? Where does the restriction that (d_mu phi) is dependent on phi come back in?
  18. P

    Variation of rubber with temperature

    My materials professor told me the restoring force of rubber increases with temperature because of entropy. At normal solid forms because the structure is energetically favorable. He says the unstreched state is entropically favorable. Is this reasonable? I plan to test it this weekend when...
  19. T

    Variation of the quadratic formula?

    http://www.mste.uiuc.edu/users/exner/ncsa/quad/ There's another way of writing the quadratic formula...but how do I derive the 2nd formula using the 1st one? I've tried for hours and I can't get it. I would really appreciate any help.
  20. S

    Calculate Change in V_EB and V_CE with Variation in Temp

    Consider a pnp transistor with {v_{EB}=0.7V and {i_{E}=1mA. Let the base be grounded and the emitter be fed by a 2 mA constant current source , and the collector be connected toa -5V supply through a 1-Killoohms resistance. if the temperature increases by 30 degree celsius, find the change in...
  21. B

    Speed of Sound in Ideal Gases: Variation & Derivation

    how does the speed of sound vary with temperature in an ideal gas? how do we derive this relation?
  22. P

    Solve differential equation with variation of parameters

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

    Understanding Variation of Parameters in Linear Differential Equations

    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) =...
  24. R

    Special Relativity and Mass Variation

    Please correct me if I am wrong, but it is my understanding of Special Relativity that the faster a particle moves the more force it requires to accellorate - laymans terms: becomes more massive. I had a post earlier where I tried to present this in the framework of an "atomic pop gun". I was...
  25. H

    Solving Direct Variation Problem: 1-y = 2x

    I am having a lot of difficulty with this problem . I don't have the slightest idea on how to do this problem and my textbook does not explain it. Please help me: Determine whether 1 - y = 2x is a direct variation. If so explain. This problem has me stumpted and very frustrated...
  26. RadiationX

    Solving D.E. with Variation of Parameters Technique

    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...
  27. D

    Variation in Real World Examples: Types, Features, and Relationships

    URGENT maths - variation assignment HEy got to make a poster and contain at least 3 'real' examples of variation. Direct, inverse, joint, part variation should be featured. for each example show -the type of variation, - an explantion of that particular type of variation, and the...
  28. S

    What Does Expected Return Mean in Coefficient of Variation?

    Please give me some hints on resolving this problem. Thanks! For example there are 3 persons who run 2, 2 and 2 metres. n=3 and the mean of the metres is 2. Standard deviation is 2 (let us pretend so). The formula for Coefficient of Variation is ; Standard deviation/ Expected return. I...
  29. C

    What are the steps for finding u1 and u2 in the variation of parameters method?

    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 =...
  30. T

    Problem using variation of parameters

    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)...
  31. D

    Is This Function a Variation of a Hyperbola?

    hi i got this equation y= x^2 - 2x + 1 / X^2 -x - 2 how do i sketch this finding all intercepts, and asymptotes with a gfx calculator? Please check if the steps i did below is right what i did i factorised the equation so i got y= (x-1)^2 / (x+1)(x-2) ASYMPTOTES the bottom line...
  32. M

    How to Find Geodesics on a Curved Surface Using Calculus of Variations

    hi, we have just got to the point in my physics course where Newtons laws are now longer that easy to work with anymore and we are now beginning to reformulate those using variational methods, and I am a little confused on one of the problems. The shortest path between two points on a curved...
  33. B

    Why does changing an x-value affect the mean but not the variation?

    mathematically why does the mean change when an x-value is changed in a list, but the variation doesn't. if someone could show me a relevant formula which can satisfy this or any other info i would be very grateful for thnak you
  34. F

    How Does Total Variation Relate to the Integral of the Absolute Derivative?

    problem: Let f \in BV[a,b] . Then \int_{a}^{b} |f'| \leq T_a^b f where T_a^b f is the total variation of f over [a,b]. there are some lemmas, etc that got me this far: \int_{a}^{b} f' \leq f(b)-f(a) = P_a^b - N_a^b \leq P_a^b + N_a^b = T_a^b f where P is the positive variation & N is the...
  35. B

    Light bulb temperature variation

    as part of a physics practical write up i have to measure the temperature of a light bulb envelopes temperature as the voltage increases. first ... am i right in thinking a type J exposed thermocouple would do the trick for this? if so, i heard something about one end being cold, to...
  36. M

    Projectile motion variation of range

    For a launched projectile, what are the following theoretical relationships/proportionalities: variation of range with speed of projectile, keeping a constant launch angle variation of range with launching angle, keeping the launching speed constant thanks for the help
  37. M

    Variation of the Double Slit Experiment

    This experiment which is a variation of the double slit experiment , has actually been conducted. We have (a) the source of electrons, (b) screen 1 ( with the double slit ) and finally (c) screen 2 , where the particles are registered. Near the slits in screen 1 and on the far side from the...
  38. N

    Standard Model Particle Variation

    The Standard Model of particle physics provides no explanation for the masses of the basic particles. If the masses were much larger- a possibility for a variation of the model- then a small collection of particles could collapse in a black hole. Of course this universe would be different from...
  39. D

    How Does a Toroidal Inductor Affect Velocity in a Motional EMF Setup?

    I have a variation of the Motional EMF in Tiplers Physics Second Edition 28-1. A conducting rod of mass m and length l sliding along conducting rails connected by a resistor with a uniform magnetic field normal to the movement of the rod. The variation is that instead of just a resistor, the...
  40. M

    The math of physics - Calculus of Variation?

    We escape the problems of particle physics by exploring the higher dimensions of String theory. When we have questions about String theory, we jump to the higher dimensions of M-theory to answer them. And some have purposed to use the higher dimensions of F-theory to answer questions about...
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