Recent content by elessar_telkontar

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    What's the transformation law for the permutation

    What's the transformation law for the permutation (or Levi-Civita) symbols?
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    Maths: Trigo - Which is Positive When 90° < x < 180°?

    I have a mnemotecnic rule for remember the signs of the 3 basical trigonometric functions, however this is in spanish, and I can't get a english version. The rule reads: CUST where C is cosine S sine and T tangent, and U is a connector that has no mathematical sense (If we don't put U the...
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    Why Does L' Hopital's Rule Fail for This Limit?

    I never said LH has failed. In fact if you see what i have wrote I say that the only thing is that LH is not inteded for this limits. And dextercioby, I think that is not elegant. In mathematics and physics I have learned that a elegant thing is some thing that is symmetric and has a simple...
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    Why Does L' Hopital's Rule Fail for This Limit?

    I think the L'Hospital Rule is not failing, simply for certain problems is not necessary since problems of this kind are resolvable by algebraic methods since they are pseudoindeterminate forms. Something like this is, too, when a limit that implies a functions like sines, cosines or...
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    Matrix of linear transformation

    Well, you may to remember that the matrix of a homomorphism or linear application, or transformation between to vectorial spaces is defined by the results of applying trasformation to basis vectors of any basis of the origin space (in this case a basis of \mathbb{R}^{3}). This is not...
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    How to Expand a Vectorial Function into a Taylor Series?

    I'm trying to demonstrate the following proposition: Let \vec{\alpha}(s) be a natural parametrization of an arc C. Then: \vec{\alpha}(s+h)=\vec{\alpha}(s)+\left(h-\frac{\kappa^2h^3}{6}\right)\hat{t}+\frac{1}{2}\left(\kappa...
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    What Is the Planck Radiation Formula for Wavelength?

    I'm taking a course on astrophysics, and at this time I get the astrophysics of stars. In this section, I have to use the Planck radiation formula, but I have got it for the frecuency of radiation. What's the one for wavelenght? I have found one but I tried to reconstruct the one for frecuencies...
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    Integrating the Brachistochrone Problem: Solving for the Optimal Path

    I am gathering my mechanics notes and I put into it some examples. When I get the Hamilton principle I put a section for some basic variation calculus. There's the problem of brachistochrone, I try to solve it, but I get stuck with a integral: the integral that I should make minimal is (I'm...
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    Angular Momentum: Constant Axis & Non-CM Axis

    yes...partially. because that ecuation states that angular momentum is parallel to angular velocity, and I know it's only valid when the rigid body is rotating around a principal axis. Then, what's the most general eq?
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    Angular Momentum: Constant Axis & Non-CM Axis

    the angular momentum L is L=rxmr. for a discrete system is only the summation to all particles. but I have used then the equation of movement for rotation, that says the variation with time of angular momentum is equal to the torque. d/dt(sum(rxmv))=sum(rxF), d(L)/dt=T If I take a...
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    Angular Momentum: Constant Axis & Non-CM Axis

    well. I have another question: Is there a relation between the angular momentum about an axis passing through CM and other angular momenta passing through other points of the rigid body, like the Parallel axes theorem for moments of inertia?
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