Re: what is x^dx equal to?

From	Sergio <invalid@invalid.com>
Newsgroups	sci.math
Subject	Re: what is x^dx equal to?
Date	2018-10-02 19:34 -0500
Organization	Aioe.org NNTP Server
Message-ID	<pp12q3$mtg$1@gioia.aioe.org> (permalink)
References	(4 earlier) <2f0345f4-2b90-4aec-ac75-67eede259d56@googlegroups.com> <19b65ce7-903f-4fe0-bd97-cadd63fa9d1c@googlegroups.com> <5799198e-e3f2-45a0-919e-6793a98246f8@googlegroups.com> <e4117afc-cec3-4a81-ad99-7d247b7acdb8@googlegroups.com> <5ad91854-a9c8-4f6b-a9c5-7d73209afd5b@googlegroups.com>

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On 10/2/2018 3:48 PM, 7777777 wrote:
> tiistai 2. lokakuuta 2018 10.36.47 UTC+3 Zelos Malum kirjoitti:
>> Den tisdag 2 oktober 2018 kl. 08:20:42 UTC+2 skrev 7777777:
>>> tiistai 2. lokakuuta 2018 8.34.41 UTC+3 Zelos Malum kirjoitti:
>>>>> no, it is not meaningless. 
>>>>
>>>> You can give it meanign but if you say it is from dy/dx=f'(x), then it is meaningless cause dy nor dx does not refer to a function, value or anything on their own, but together they do.
>>>>
>>>> He assumed you meant a value of some sort (at which it is correct) but you are not refering to a value with your previous statement. Therefore it is wrong.
>>>>
>>>> you can defien dx^2=0, we got nilpotent structures and such, but it is not like dy/dx=f'(x) then.
>>>
>>> It is not wrong.
>>>
>>> What function does dx refer in e^dx = 1 + dx ?
>>>
>>> It comes from x^dx = 1 + ln x dx when x = e
>>
>> The it is not the same as in dy/dx=f'
>>
>> it is somethign else that you haven't specified, some real number presumibly
> 
> y = f(x) = e^x 
> 
> f'(x) = dy/dx 

where f(x) = y

> = (f(x+dx) - f(x))/dx 

you left out the limit going to 0
f'(x) = limit as dx=>0 of ((f(x+dx) - f(x))/dx

> =( e^(x+dx) - e^x )/dx =

you left out the limit going to 0 again......

so sorry, https://en.wikipedia.org/wiki/Fundamental_theorem_of_calculus

> (e^x * e^dx - e^x)/dx = e^x(e^dx - 1)/dx = e^x((1+dx) - 1)/dx = e^x 
> 
> so e^dx = 1 + dx 
> and 
> dx is the same as in f'(x) = dy/dx
>

Thread

what is x^dx equal to? 7777777 <jussir@yahoo.com> - 2018-09-29 03:54 -0700
  Re: what is x^dx equal to? Roland Franzius <roland.franzius@uos.de> - 2018-09-29 13:43 +0200
    Re: what is x^dx equal to? 7777777 <jussir@yahoo.com> - 2018-09-29 09:33 -0700
  Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-09-30 22:55 -0700
    Re: what is x^dx equal to? 7777777 <jussir@yahoo.com> - 2018-09-30 23:08 -0700
      Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-09-30 23:23 -0700
        Re: what is x^dx equal to? 7777777 <jussir@yahoo.com> - 2018-10-01 11:05 -0700
          Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-01 22:34 -0700
            Re: what is x^dx equal to? 7777777 <jussir@yahoo.com> - 2018-10-01 23:20 -0700
              Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-02 00:36 -0700
                Re: what is x^dx equal to? 7777777 <jussir@yahoo.com> - 2018-10-02 13:48 -0700
                Re: what is x^dx equal to? Sergio <invalid@invalid.com> - 2018-10-02 19:34 -0500
                Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-04 00:02 -0700
                Re: what is x^dx equal to? 7777777 <jussir@yahoo.com> - 2018-10-04 11:03 -0700
                Re: what is x^dx equal to? Sergio <invalid@invalid.com> - 2018-10-04 13:36 -0500
                Re: what is x^dx equal to? 7777777 <jussir@yahoo.com> - 2018-10-04 11:52 -0700
                Re: what is x^dx equal to? Sergio <invalid@invalid.com> - 2018-10-04 20:59 -0500
                Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-04 22:26 -0700
                Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-05 00:24 -0700
                Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-05 00:24 -0700
                Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-05 00:24 -0700
                Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-05 00:24 -0700
                Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-05 00:24 -0700
                Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-05 00:25 -0700
                Re: what is x^dx equal to? Python <python@python.invalid> - 2018-10-04 21:39 +0200
  Re: what is x^dx equal to? Mathedman <Mathedman@hotmail.com> - 2018-10-02 09:10 -0500
  Re: what is x^dx equal to? Jan <filmart@gmail.com> - 2018-10-02 09:25 -0700
  Re: what is x^dx equal to? Sergio <invalid@invalid.com> - 2018-10-02 19:35 -0500
  Re: what is x^dx equal to? Mathedman <Mathedman@hotmail.com> - 2018-10-07 08:47 -0500
    Re: what is x^dx equal to? Zelos Malum <zelos.malum@gmail.com> - 2018-10-08 01:17 -0700

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