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May
14
reviewed Approve Why does $\sin(0)$ exist?
May
14
comment Discrete Laplace Tranform.
I asked a similar question here: math.stackexchange.com/questions/793550/… - what I find strange though is that while you can also read that the Laplace transform is the continuous analog of the dot product for infinite dimensional vectors (=functions) you still calculate infinitely many terms in the discrete version (and not just over the available dimensions of your vectors as with the dot product) - perhpas you could contribute :-)
May
14
comment Discrete Laplace Tranform.
I asked a similar question here: math.stackexchange.com/questions/793550/… - what I find strange though is that while you can also read that the Laplace transform is the continuous analog of the dot product for infinite dimensional vectors (=functions) you still calculate infinitely many terms in the discrete version (and not just over the available dimensions of your vectors as with the dot product) - perhpas you could contribute :-)
May
14
comment Example for finite dimensional analog of integral transforms
@MattL.: Thank you, what still bothers me with this finite version is that the sum is over infinitely many terms because the dot product is only over the available dimensions.
May
13
reviewed Approve Trigonometric substitution
May
13
comment Example for finite dimensional analog of integral transforms
@MattL.: I had a quick look at it and it looks promising - so first thank you! Could the $z$ also be real valued like e.g. $2$?
May
13
comment Example for finite dimensional analog of integral transforms
@MattL.: To be honest with you I don't know because I don't know the Z-transform well enough. But perhaps you could give an example that contains the elements I asked for in my question?
May
13
asked Example for finite dimensional analog of integral transforms
May
9
awarded  Notable Question
Apr
28
awarded  Nice Question
Apr
28
revised Intuition for complex eigenvalues
edited title
Mar
9
accepted Intuition and counterexamples for higher-order derivative test
Mar
8
comment Intuition and counterexamples for higher-order derivative test
I was just talking about your example: In our axiomatic system it is not defined at point $0$ because you are dividing by zero there! I am not talking about nature but only about things happening within the realms of pure maths. Yet could you give me a reference for the number of smooth functions and formulas accessible? Thank you again.
Mar
8
comment Intuition and counterexamples for higher-order derivative test
The intuition is appealing - thank you and +1! Considering your example: I disagree: It does not have a minimum at zero - it has literally nothing at zero because it is not defined there, neither are any of its derivatives (see also comments to my question).
Mar
8
comment Intuition and counterexamples for higher-order derivative test
Is it possible to find a counterexample where you don't have a separate case at the extreme value (as with this example at $0$)? This feels a little bit like cheating because the "original function" is not defined at this point.
Mar
8
comment Intuition and counterexamples for higher-order derivative test
Thank you Daniel: $x^{12}$ doesn't answer my question concerning an intuition. Even $x^4$ would work as an example, this is not the problem.
Mar
8
asked Intuition and counterexamples for higher-order derivative test
Feb
25
reviewed Approve How do I solve $y'=\frac{y}{x}\frac{x-y}{x+y}$?
Feb
25
reviewed Approve Integral equation and constant rules
Feb
25
reviewed Approve Factoring $x$ out of the denominator of a limit