Condition Definition and 587 Threads

  1. 7

    How to put a condition for printing in mathematics

    Hi All , what I am trying to do is, after getting so many solution I just want to print only the intger solution: For[n = 0, n ≤ 10, n++ Do[Print[{n, (n - Sqrt[Sqrt[ 2]Sqrt[3n^2 - 9n + 8] + 3n - 4])/2, OTHER SOLUTION, (n - Sqrt[-Sqrt[2]...
  2. H

    Question in Proof of second order condition with linear constraints

    http://www.math.northwestern.edu/~clark/285/2006-07/handouts/lin-constraint.pdf It's actually proof of finding sign definiteness of quadratic form with linear constraints with sign of submatrices of bordered hessian. The proof is from page 2~page 3. I have 2 questions: 1. From about...
  3. G

    Cauchy vs. Dirichelt/Neumann Condition for PDE

    Hi, Can anybody tell me the difference between a Cauchy Boundary condition and a combined Dirichlet/Neumann Boundary Condition for PDEs? The reason why I'm asking is because Cauchy boundary conditions can be used to solve Open Hyperbolic PDEs, whereas Dirichlet/Neumann can only be used to...
  4. T

    Condition for periodicity of linear combination of signals

    What is the condition for the continuous time signal x(t) to be periodic if it is the linear combination of n periodic signals. where x(t) = a_{1}x_{1}(t)+a_{2}x_{2}(t)+a_{3}x_{3}(t)+......a_{n}x_{n}(t) where x_{i}(t) is periodic with fundamental period T_{i} \forall i, where i \in...
  5. S

    Integral vs differential curl theorem implicit condition

    Faraday's law has an integral and a differential version: curl \mathbf{E} = - \frac{\partial \mathbf{B}}{\partial t} \mbox{ and } \oint_{C} \mathbf{E} \cdot d \mathbf{l}=- \frac{d}{dt} \int_{S} \mathbf{B} \cdot d \mathbf{S} When I use the differential version I always have a constant of...
  6. B

    What condition defines a principal stress?

    What condition defines a principal stress? thx
  7. I

    Boundary condition for magnetic vector potential

    Hi I am studying magnetic vector potential from Griffiths book. The eq 5.76 in his book gives the boundary condition for the magnetic vector potential. \frac{\partial \vec{A_2} }{\partial n}- \frac{\partial \vec{A_1} }{\partial n}=-\mu_o \vec{K} where n is the vector perpendicular to the...
  8. K

    Can someone state clearly a sufficient condition for a 4-tuple of

    Can someone state clearly a sufficient condition for a 4-tuple of quantities to be a four vector? For instance I saw the naive definition of speed four vector is not but I couldn't really understand when a 4-tuple is or is NOT a four vector.
  9. S

    Understanding Navier's Slip Condition: Fixed Walls & Applicability

    Is it necessary for the channel walls to move for the applicability of Navier's slip condition at the boundary. i.e., Is it possible that the channels walls are fixed, but we can apply the Navier's slip condition at both the channel walls.
  10. H

    What Determines the Number of Real Roots in a Quadratic Equation?

    Homework Statement State the condition for the equation px^2 + qx + r = 0 to have: a)two different real roots b)two equal real roots c)no real rootsHomework Equations b^2-4ac maybe?The Attempt at a Solution I missed a class due to ailments and now have to catch up on missed work. I can't find...
  11. A

    Understanding Electrical Motor Failure Condition Data

    Hi Guys, I have some data on a small electric motor being run continuously for a year. The problem is I only have the Headings and numbers and no units or information on what devices were used to measure the data. The variables measured were Time, Speed, Temperature, Power, Powerfactor...
  12. Y

    Question on an example relating to magnetic boundary condition.

    This is an example shown in "Introduction to Electrodynamics" by Griffiths. Page 226 example 5.8. Given a sheet of current K on the xy-plane where current traveling in +ve x direction. Find the magnetic field. I am confused on the way the book justify the z direction of B is zero. The...
  13. N

    How to Solve the Initial Condition Problem for Finding A_x and A_y Expressions?

    i can't see how they got X and Y expressions V_x is the derivative of X(t) by t 'A' and phi are needed to be found but when i don't know how to innpur the initial condition to find A_x and A_y because when we integrate x' expression bot sides i get x(t)-x(0)=[A_x*cos(wt+phi)]/w -...
  14. O

    Solution for u_x+2xy^2u_y=0 with Initial Condition u(x,0)=\phi (x)

    PDE--initial condition Homework Statement Solve the equation u_x+2xy^2u_y=0 with u(x,0)=\phi (x). Strauss PDE 2nd ed., chapter 1.5, exercise 6. Homework Equations The question is under "Well-Posed Problems" section, so this might be about existence, uniqueness, or stability. The...
  15. M

    Find the Error: Modifying Euler's Method for Initial Condition y(5)=3

    Euler's method? Describe how to modify Euler's method to deal with the initial condition of y(5)=3 instead of y(0)=3. Use this on the equation y'=1+t using a time step of 0.1 and initial condition of y(5)=3 and find y(5.4) . ?? Now find the exact solution of this equation using calculus...
  16. S

    Condition for a particle to move relativistically

    What is the condition required for a particle to move relativistically?
  17. L

    Reissner- Nordstrom metric- weak energy condition

    Hey, For a problem I am working on I need to know if the energy-momentum tensor of the Reissner- Nordstrom metric obeys the weak energy condition. Since I need the result for the following calculations, I just want to be sure that it is correct. Does anyone of you know the correct answer and...
  18. P

    Sufficient Condition for a Quadrilateral to be a Trapezium

    what is the sufficient condition on a quadilateral to be a trapezium ?
  19. A

    Solving Separable Differential Equation with Initial Condition

    QUESTION: Solve the separable differential equation dy/dx = sqrt(4y+64), Initial Condition: y(4)=9, and find the particular solution satisfying the initial condition. MY ATTEMPT: (dy/dx)^2 = 4y+64 ((dy/dx)^2)-4y = 64 ,/' (((dy/dx)^2)-4y) dx = ,/' 64 dx Is this the right method...
  20. D

    Finding Auxiliary Conditions for u(x,y) and Solving for ω(ξ,η)

    2.2.2 3u_x+4u_y-2u=1\Rightarrow \omega_{\xi}+k\omega=\varphi(\xi,\eta) u(x,y)=u(\xi\cos{\alpha}-\eta\sin{\alpha},\xi\sin{\alpha}+\eta\cos{\alpha})=\omega(\xi,\eta) u_x=\omega_{\xi}\cos{\alpha}-\omega_{\eta}\sin{\alpha} u_y=\omega_{\xi}\sin{\alpha}+\omega_{\eta}\cos{\alpha}...
  21. N

    Are there any regulating condition on the spin of particle?

    Please teach me this: Are there any regulating limit on spin of particle?.E.g why spin of electron is 1/2 but not 3/2,spin of photon is 1 but not 2 e.t.c Thank you very much in advance.
  22. C

    Numerical Error/Large Condition number

    Hi there, I am working on a problem in Fluid dynamics. I've written a code in MATLAB which finds the shape of the free surface of the liquid based on Newton Relaxation. The code is fairly robust and produces good results which agree with current papers on the same problem. Unfortunately...
  23. G

    Physical meaning of Neumann boundary condition

    I'm playing with the PDE toolbox in Matlab and solving Laplace's equation, ∇2V = 0, for various electrostatic geometries. I say 'playing' because I started in the wrong end (or right end, depending on how you look at it) by simple trial and error until the solutions looked like something...
  24. M

    Initial Condition Problems with Heat Equation in Mathematica

    I've been trying to work through the heat equation given in this Sous Vide cooking primer: http://amath.colorado.edu/~baldwind/sous-vide.html It gives a modified version of the heat equation with a shape parameter for simplification. The equations are shown below...
  25. E

    Transitivity condition for Einstein synchronization and the one-way light speed

    1) Consider that one way light speed is anisotropic. 2) Use the Einstein method to synchronize all the watches by the watch located at (x,y,z)=(0,0,0). Now, all the watches are synchronized by the watch at (0,0,0) but they are not necessarily synchronized with each-other (Consider watches...
  26. O

    Does the Lorentz Condition Apply to the Given Vector Field Lagrangian?

    Homework Statement Given the Lagrangian density L=-{1 \over 2}[\partial_\alpha\phi_\beta(x)][\partial^\alpha\phi^\beta(x)]+{1\over 2}[\partial_\alpha\phi^\alpha(x)][\partial_\beta\phi^\beta(x)]+{\mu^2\over 2}\phi_\alpha(x)\phi^\alpha(x) for the real vector field \phi^\alpha(x) with field...
  27. C

    Three condition step function?

    Homework Statement http://img189.imageshack.us/img189/9859/mathlm.th.jpg (Click the thumbnail)Homework Equations When taking the laplace transform of derivatives L{f^n(t)=(s^n)*F(s) - s^(n-1)*f(0)...}; the step function u(t-a) The Attempt at a Solution we have never done a step function...
  28. Y

    Question about magnetostatic boundary condition.

    My understanding of: \int_S \nabla X \vec{H} \cdot d\vec{S} = \int_C \vec{H} \cdot d \vec{l} = I Means the current I creates the magnetic field in the form of \nabla X \vec{H} instead of magnetic field creates the current I. But in the boundary condition, it claims the tangential...
  29. D

    Momentum Operators and the Schwartz Integrability Condition

    Hi All, When computing the commutator \left[x,p_{y}\right], I eventually arrived (as expected) at \hbar^{2}\left(\frac{\partial}{\partial y}\left(\frac{\partial f}{\partial x}\right) - \frac{\partial}{\partial x}\left(\frac{\partial f}{\partial y}\right)\right) and I realized that, as correct...
  30. A

    Finding the Smallest Solution with Condition a: minSol Function

    'Condition' is a function which determines whether an element of some type a satisfies some property, and returns True if only if it does. A polymorphic data type 'Condition a' is defined: data Condition a = Con (a -> Bool) Define a function minSol::Ord a => Condition a -> [a] -> Maybe a...
  31. W

    Jordan wigner transform and periodic boundary condition

    i think jordan wigner transform, when applied to open boundary system, can simplify a spin 1/2 system to a free fermion system but there is a difficulty in the case of periodic boundary condition in this case, we have to deal with terms like S_N^+S_1^-=(-)^{\sum_{k=1}^{N-1}n_k}...
  32. J

    The Wave Condition: Fixed Ends and Open Ends

    Homework Statement This is what my professor wrote on the board. Suppose the condition is as follows y(0) = y(L) = 0 link to img http://www.izhuk.com/painter/image2.php?id=1286387629-69-86-215-102&md5=c054d375567134a9faa133b47fe690b2 This is the fundamental harmonic - with nodes appear at x...
  33. M

    Prove Orthogonality Condition For Sines (Integral)

    Homework Statement I need to prove the equation attached. I also have to describe why the integrals vanish. Homework Equations The Attempt at a Solution I am not sure how to begin. Our teacher told us this equation is known as the orthogonality condition for sines. I also know...
  34. M

    Qantum mechanics condition for time independence

    Homework Statement \psi(x,t) = \psi_1 e^{-i E_1 t/2} + \psi_2 e^{-iE_2 t/2} under what conditions is the probability density time independent? Homework Equations |\Psi(x,t)|^2 = \psi(x,t)* \psi(x,t) The Attempt at a Solution i found a statement in pg 71 of prof Richard...
  35. A

    Confused with sufficient and necessary condition

    Homework Statement i know that "A is necessary for B" means "B implies A". but i confused with the word "A is necessary of B" somebody help
  36. P

    Final condition instead of initial condition

    Let's consider a second order differential equation f(x,\dot x,\ddot x,t)=0 and let's suppose that f satisfies all the conditions of the Cauchy Theorem, i.e. f is such that the equation above with the initial conditions x(t_0)=x_0\qquad\dot x(t_0)=v_0 has an unique solution in a...
  37. Z

    A question about Caratheodory condition.

    This question comes from Theorem 16.3 of Bartle's "The Elements of Integration and Lebesgue Measure", in page 163. The condition E\subseteq A is indeed needed in the proof of necessary condition, but I did not find its usage anywhere in the proof of sufficient condition, for example...
  38. R

    Your physical shape and condition

    Are you satisfied with your current weight and level of fitness? If so, what do you do to maintain it? If not, why do you think you have fallen from it (assuming you were once there)?
  39. A

    Proving equations for a plane stress condition

    Homework Statement For a plane stress condition (stress z-axis = 0 ), prove the following relations if strain x-axis and strain y-axis are determined by experiments. σ_x=(∈_x+v∈_y/1-v^2)E & σ_y=(∈_y+v∈_x/1-v^2)E where: σ_x = stress in x-axis σ_y = stress in y-axis ∈_x = strain...
  40. A

    Epsilon, delta condition for limits questions

    Homework Statement Ok so this may get a little drawn out here because my book only gives me one example and I guess I can't decipher its meaning. So here is the example they give: For \;\; \lim_{x \to 2} x^{2} = 4 Find a \;\; \delta > 0 \;\; such that whenever 0 < |x-2|< \delta, \;\;\...
  41. G

    Hausdorff condition in differential manifold definition

    Dear all, why is it needed in the diff manifold definition that the base set M is topologically Hausdorf ? Since M is locally homeomorphic with Rn as metric space is Hausdorf, shouldn't this condition be automatically satisfied? Thanks. Goldbeetle
  42. M

    Condition for differentiability

    What's the condition for f(x,y) to be differentiable in its domain? I googled for it but couln't find... Thanks in advance.
  43. S

    Are These Reactions Possible? Understanding Conditions for 2NaOH+K and HCN+K

    hello, I would like to know if following reactions are possible/correct and under what condition: 2NaOH+K->KOH+NaOH and HCN+K->KCN+H Theoretically it should be possible but I'm not sure,Please help me understand Thanks
  44. P

    Boundary condition for Maxwell equations

    It's obvious that if Maxwell equations are fulfilled by some E(x,y,z,t) and B(x,y,z,t), they are also fullfiled by E(x,y,z,t)+ E_0 and B(x,y,z,t)+B_0, where E_0 and B_0 are constants. This freedom has physical significance as it changes the Lorentz force which act on a charge. It...
  45. Z

    Why Can't You Raise Your Leg Sideways Against a Wall?

    Homework Statement stand with one arm and the side of one foot pressed against a wall. can u raise the other leg side ways?if not then why not? Homework Equations The Attempt at a Solution i tried myself but couldnot raise.i m not getting the reason.
  46. M

    What Are the Conditions for Solving f(x,t) in the Problem?

    Hi, it is possible to solve the following problem, I mean give at least some conditions on f(x,t)? \int_0^{\infty}e^{-x}[f(x,t)+g(t)] xdx=g(t)
  47. S

    Necessary and sufficient condition for inequality

    Homework Statement consider two conditions x2-3x-10 < 0 and |x-2| < A on a real number x, where A is positive real number (i) find the range of values of A such that |x-2| < A is a necessary condition for x2-3x-10 < 0 (ii) find the range of values of A such that |x-2| < A is a sufficient...
  48. M

    Will a PRV operate at zero-flow condition?

    I am working on a project that involves the hydraulic design of a potable water transmission line (diameter 500mm), that conveys water from the source location of elevation 1500m to the end point at an elevation of 950m. The hydraulic design requires several PRVs along the path (around 230Km...
  49. P

    Magnetostatics - boundary condition

    Let's consider two media with magnetic permeability \mu_1, \mu_2 . What's the condition for magnetostatic vector potential \vec{A} on the boundary. Is it true that its tangent component should be continuous. Thanks for replay.
  50. B

    Question regarding GR and the cylinder condition

    Question regarding GR and the "cylinder condition" Im reading that in Kaluza-Klein theory, the derivatives (of the metric g_{\mu\nu} with respect to the 5th dimension, X^4 , were chosen to be zero, to explain why we do not "feel", or detect, the existence of X^4 i.e. the Cylinder Condition...
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