Recent content by ibysaiyan

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    Integral of 1/sqrt(x²+1) and a differential equation identity

    I was under the impression that maybe there is a way of showing the above relation, but now it all makes sense. Thanks for the clarification.
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    Integral of 1/sqrt(x²+1) and a differential equation identity

    Guys thanks for the responses. My issue is still not resolved. Let me rephrase the question. I want to know how one can show that \int dx/y = \int d(x+y) / (x+y)
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    Integral of 1/sqrt(x²+1) and a differential equation identity

    This is why I am stumped. I am referring to the bottom most solution posted on the following link by juantheron (user): http://math.stackexchange.com/questions/610733/how-to-integrate-int-dx-over-sqrt1-x2?lq=1
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    Integral of 1/sqrt(x²+1) and a differential equation identity

    You have misunderstood my post. I want to know why dx/y = dy/x = \int d (x+y) / (x+y) = ln (x+y) + C Thanks.
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    Integral of 1/sqrt(x²+1) and a differential equation identity

    Homework Statement Hi I am trying to solve an indefinite integral of the form 1/ sqrt[ (x^2 +1)] dx.. Homework Equations The Attempt at a Solution Different ways of solving it are posted on the link below. I would like to know the following result : dx/y = dy/x = d...
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    Limit Definition Derivative: e^(-1/x)

    Thanks for the explanation, apologies if I have annoyed you.
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    Limit Definition Derivative: e^(-1/x)

    I was referring to the second part of the question. Suppose f(x) = e^(-1/x) f'(x) = \lim_{h \to 0} e^{(1/x+h)} - e^{(1/x)} / h A taylor expansion about e^-{(1/x)} = \sum_{n=0} ^ \infty - (1/x^n) /n! f'(x) = \lim_{h \to 0} (-1 - 1/{(x+h)}) - (-1 - {1/x}) / h f'(x) =...
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    Limit Definition Derivative: e^(-1/x)

    This problem has caught my attention.. I was thinking of using binomial expansion for e^(x+h)^-1 term and then to apply e^k -1 / k = 1 as lim k--> 0
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    Why do odd parity terms vanish in the harmonic oscillator expectation value?

    Hi vela I have fixed few typos so it should be clear now.
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    Why do odd parity terms vanish in the harmonic oscillator expectation value?

    Actually... I think I get it now... (below is what I think happens} Is it because \Phi(x) = -\Phi(-x)(odd) and f(x) = f(-x) (even)... Integral of odd*even = integral of odd = zero . Also for the other two integrals(with exponential) they are defined as "symmetric limited function"...
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    Why do odd parity terms vanish in the harmonic oscillator expectation value?

    I was in a rush hence my lack of input. Here is what I get after expansion: \Psi(x,t) = 1/\sqrt{2} (\Psi_{0}(x,t) + \Psi_{1}(x,t) \Psi_{0}(x,t) = \Phi(x) e^{-iwt/2} and \Psi_{1}(x,t) = \Phi_{1}(x) e^{-i3wt/2} \left\langle\psi \left|x\right| \psi \right> = 1/\sqrt{2}...
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    Why do odd parity terms vanish in the harmonic oscillator expectation value?

    Hi, Homework Statement A quantum harmonic oscillator is in a superposition of states(below): \Psi(x,t) = 1/\sqrt{2} (\Psi_{0}(x,t) + \Psi_{1}(x,t) \Psi_{0}(x,t) = \Phi(x) * e^{-iwt/2} and \Psi_{1}(x,t) = \Phi_{1}(x) * e^{-i3wt/2} Show that <x> = C cos(wt) ...Homework Equations Negative...
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    Graduate What is the Color of a Neutron Star?

    Oh yes, that makes sense. I was getting mixed up between neutron stars and white dwarfs since they both are stabilized by degeneracy pressure. Does this mean the star on the whole is neutral ,as someone else before me suggested (above) but how can it be like that when we know neutron stars have...
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    Graduate What is the Color of a Neutron Star?

    Don't neutron stars consist of a sea of degenerate electrons and angular momentum ? Would that have any bearing to their EM spectrum.
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    Why Does Integration by Parts Yield Extra Δk in Wave Packet Analysis?

    Ok.. so I have just used the identified that I previously mentioned.. I still don't end up with the form in the OP. $$\left.\frac{A}{x}\sin k'x\right|_{k-\Delta k}^{k+\Delta k} = \frac{A}{x}[\sin ((k+\Delta k)x) - \sin((k-\Delta k)x)].$$ Now sin (a+b) = sinAcosB+sinBcosA , sin (a-b) =...