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1h
comment Analytical solution for bound state energies of infinite well
I think you have asked this before and were given some advice on how to formulate an acceptable question. Please heed that advice and state your specific Mathematica problem. I suspect this is a homework problem.
1h
answered Mathematica 8 remove black background from image
2h
comment Why doesn't FullSimplify simplify expressions with DiracDelta?
@BobHanlon Yes, that's right, either way is fine (and if for some reason one way doesn't work, you can always try the other order to make sure).
8h
answered Why doesn't FullSimplify simplify expressions with DiracDelta?
15h
comment Superscript prime symbol
Very closely related: How to Clear variables with apostrophe? There, I suggest using a different unicode glyph that looks better.
1d
reviewed Close Defining a Gaussian Distribution Fit to data
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reviewed Close Calculating Value-At-Risk (VaR) in Mathematica. A simple code
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reviewed Close FindFit with PolyGamma function
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reviewed Close How to regress negative log?
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reviewed Close Non-aggregated solution for NonlinearModelFit
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reviewed Close NonlinearModelFit::nrlnum error using FindFit /NonlinearModelFit
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comment Derivative of an expression containing a symbolic sum
Yes, that's right.
1d
comment Derivative of an expression containing a symbolic sum
@StripesPlaid Indeed, the last simplification works in Mathematica version 10.0.1, but not in version 8. I'm guessing you're using an older version. The TagSetDelayed rule for $\beta$ only gets applied in the 10.0.1 version after the derivative has been done under the sum. Then what the rule says is that whenever $\beta$ appears as the summation index without any additional range specification, and there is a Kronecker delta involving $\beta$, you're supposed to reduce the sum to the rest multiplying the delta.
2d
answered Derivative of an expression containing a symbolic sum
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comment Derivative of an expression containing a symbolic sum
This is probably a duplicate of how to differentiate formally. You only have to get rid of the Subscripts as variable names because they bury the meaning of the actual labels $\alpha$ and $\beta$ too deeply. Replace Subscript[lambda][alpha] by lambda[alpha] etc.
2d
comment How to tell Eigensystem the type of the elements comprising a matrix I would like to diagonalize
@lagoa But that time is negligible compared to the computation of the eigensystem.
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reviewed Close a complicated Sum
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reviewed Close Concisely returning a position in an array with an index variable
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comment How to tell Eigensystem the type of the elements comprising a matrix I would like to diagonalize
It's not clear to me what you mean. Are you trying to find a symbolic solution first by using assumptions, or do you want to define a function that takes a numerical argument and returns the Eigensystem, or is M already numerical but written in terms of arbitrary-precision numbers, or something else? Please include a minimum example to clarify what you're trying to do.
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comment How to use a symbol with subscript as a variable?
If you enter the sub and superscripts without quotation marks, then none are displayed, right?