Q1:
If f(X)=X+X+X+...+X (X times) then what is a Derivative of f(X)?and Why?

Question

Q1:
If f(X)=X+X+X+...+X (X times) then what is a Derivative of  f(X)?and Why?

kinggeorge · Answer

strictly speaking, you can't take a derivative since this function is only defined for natural numbers.

asnaseer · Answer

I had asked this question quite a while back and it generated a lot of discussion.
If you are interested then I can post a link to that question here.

anonymous · Answer

Ok but suppose to it is exist.and I want to find out the value.

anonymous · Answer

Ok asna what was your answer?

asnaseer · Answer

http://openstudy.com/updates/4f08846ee4b014c09e63b93d

kinggeorge · Answer

We would need a different derivative to even suppose this had a derivative. The derivative you learn in calculus simply won't cut it here.

anonymous · Answer

ansa I saw the post but I didn't find an a reasonable answer.
King I know what you think.but as a Economist,Socialist or somebody who not actually involve  
with mathematics  I would like to find out an answer.
So you can define a reasonable Derivative then answer to the Question.

asnaseer · Answer

the conclusion from the linked question was that derivatives are only defined for "continuous" functions. the function you have listed is not continuous and hence does not have a derivative.

anonymous · Answer

But you know we have no any continuous functions in the world so we have to correct our definitions.

kinggeorge · Answer

But in the world, it is often far easier, and just as accurate, to model things with a continuous model rather than discrete.

anonymous · Answer

Ok try to solve with a new model.I am looking for the best model.

anonymous · Answer

what youre asking for could be enough work to form a thesis <.< its not something that can be answered easily, much less on a forum like this =/

anonymous · Answer

The one of the important function and useful in Engineering is  IMPULSE function.
But it is not a function !and if the function has not defined yet, there have not  been anythings in the world until now.

asnaseer · Answer

I don't understand what point you are trying to make here?

anonymous · Answer

Actually I would like to find out some questions which have not answered by good reason.

anonymous · Answer

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