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Oct
20
comment Why doesn't FullSimplify simplify expressions with DiracDelta?
may be because it does not know if x>y? Assuming[x > 0 && y > 0 && x > y, FullSimplify[x/y DiracDelta[x - y]]] gives zero. (I assume you are looking for zero as answer.) The point is, just telling M that x>0 and y>0, does not say anything about if x==y or not.
Oct
20
comment Find all roots in range
Solve works also: Solve[Zeta[1/2 + I y] == 0 && -10 < Abs@y < 10, y, Complexes] gives {{y -> (5 I)/2}, {y -> (9 I)/2}, {y -> (13 I)/2}, {y -> (17 I)/2}} So does NSolve
Oct
20
revised Manipulate showing the trajectory of a particle
added 63 characters in body
Oct
20
answered Manipulate showing the trajectory of a particle
Oct
20
answered `Solve` with variables as single vector
Oct
20
answered `Solve` with variables as single vector
Oct
20
answered Using conditionals to check if LinearSolve found a solution
Oct
20
comment Using conditionals to check if LinearSolve found a solution
can you post an example where LinearSolve[A,b] returns LinearSolve[A,b] and nothing else?
Oct
20
comment DSolve will not apply assumption m ∈ Integers
I do not think DSolve uses/accepts user assumptions. This was my understanding all along. Unless something changed in newer version of M.
Oct
20
answered Problem in downloading “ToMatLab” package
Oct
19
comment Derivative of an expression containing a symbolic sum
so there is going to be a term in the series in the denominator where \[Alpha]=\[Beta] This I do not understand at all. You are doing symbolic differentiation? How is Mathematica supposed to know that Alpha and Beta are the same symbol at one point?
Oct
19
comment Derivative of an expression containing a symbolic sum
appears explicitly in the numerator, and implicitly in the denominator due to the sum I do not see it. The denominator has no Subscript[\[Lambda], \[Alpha]] in it at all. The sum is over beta, not alpha. Here is screen shot of your expression !Mathematica graphics
Oct
15
awarded  Necromancer
Oct
12
comment StateResponse is non-deterministic
@Mathxy btw, It might be a good idea to send this to support@wolfram.com.
Oct
12
comment StateResponse is non-deterministic
@Mathxy As I said, I do not know internally what happens. CLearly this is a bug, but you asked for a workaround. There was some changes in v10 with processing of diracdelta's in control system. May be this is related. See mathematica.stackexchange.com/questions/57891/…
Oct
12
comment Why this gives 0?
@Anixx that is correct, that is why I used ExpToTrig to make it generate a result. Ofcourse Exp[t] and ExpToTrig[Exp[t]] are the same thing, mathematically speaking. But one gives a result and one does not. That is why. Just to see the zero come out. Else will not see it.
Oct
12
answered Why this gives 0?
Oct
12
comment Why this gives 0?
I did not notice the /w. But still, I do not see how it the final result should be Sinh[x]. I think the 0 is not correct and I know why it does it, but I do not see how you came up with Sinh[x] either. But not important. I think 0 is not correct.
Oct
12
comment Why this gives 0?
Can you explain why the result should be sinh(x)? Lets assume all is perfect, and so InverseFourierTransform[FourierTransform[Cosh[t]]] should in theory return back Cosh[t], right? (inverse(fourier(foo))) is foo. Then why is I*Cosh[h]=Sinh[x]? Where did this come from?
Oct
12
comment How to export a text into eps without splitting
it works fine for me. Version 10.01 on windows.