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Math Help - Intigrating with or without dx

  1. #1
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    Intigrating with or without dx

    Indefinite integral is simply 'reverse differential' right?...that's why dx needs to be necessarily present, since you can reverse differentiate only a differential equation.

    In indefinite integral its necessary not to have an infinitesimally term, since a real life function with this term is awkwardness...it has no meaning.

    So if suppose, the area of the differentiated equation yields the desired result, then we gotta take the infinitesimally terms to one side, and take a another function...like dy/dx = z(x) or n

    This is an assertion, so I would like to confirm.
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  2. #2
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    Quote Originally Posted by dE_logics View Post
    Indefinite integral is simply 'reverse differential' right?...that's why dx needs to be necessarily present, since you can reverse differentiate only a differential equation.

    In indefinite integral its necessary not to have an infinitesimally term, since a real life function with this term is awkwardness...it has no meaning.

    So if suppose, the area of the differentiated equation yields the desired result, then we gotta take the infinitesimally terms to one side, and take a another function...like dy/dx = z(x) or n

    This is an assertion, so I would like to confirm.
    What you've posted makes no sense whatsoever (to me, anyway).
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  3. #3
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    Quote Originally Posted by dE_logics View Post
    Indefinite integral is simply 'reverse differential' right?...that's why dx needs to be necessarily present, since you can reverse differentiate only a differential equation.
    "anti-differentiate" is the usual term and it is "differential expression" not "differential equation".

    In indefinite integral its necessary not to have an infinitesimally term, since a real life function with this term is awkwardness...it has no meaning.
    No. It is extremely important to have the "dx" or "dt" or whatever in the integral. However, it is not an "infinitesmal", whatever you mean by that. It is, rather, the limit of some " \Delta x" in the original problem.

    So if suppose, the area of the differentiated equation
    This makes no sense at all. An "equation" does not have an area. Area is a geometric concept, not algebraic.

    yields the desired result, then we gotta take the infinitesimally terms to one side, and take a another function...like dy/dx = z(x) or n

    This is an assertion, so I would like to confirm.
    That last assertion makes no sense at all. I cannot think of a sense in which it would be true.
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    Quote Originally Posted by mr fantastic View Post
    What you've posted makes no sense whatsoever (to me, anyway).
    Can you pls quote what you're not getting?...I'll try and resolve.
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    "anti-differentiate" is the usual term and it is "differential expression" not "differential equation".

    But differential equation is defined as an equation which has been differentiated and has the infinitely small terms...right?

    Indefinite integral is a way to solve differential equation...isn't it??
    No. It is extremely important to have the "dx" or "dt" or whatever in the integral. However, it is not an "infinitesmal", whatever you mean by that. It is, rather, the limit of some "" in the original problem.
    I meant the infinitely small term.

    Can you pls explain in a bit more details?


    This makes no sense at all. An "equation" does not have an area. Area is a geometric concept, not algebraic.
    I meant the area under the graph formed by the equation.
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    Quote Originally Posted by dE_logics View Post

    But differential equation is defined as an equation which has been differentiated and has the infinitely small terms...right?
    Wrong, a differential equation (at its simplest) is an equation relating a function, some or all of its derivatives up to some maximum order, and the independednt variable.

    Example:

     <br />
\left[\frac{d^2y}{dx^2}\right]^2+\frac{dy}{dx}+y=\sin(x) <br />

    or more compactly:

     <br />
f(x,y,y',y'')=0<br />

    CB
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  7. #7
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    Quote Originally Posted by dE_logics View Post
    Indefinite integral is simply 'reverse differential' right?...that's why dx needs to be necessarily present, since you can reverse differentiate only a differential equation.

    In indefinite integral its necessary not to have an infinitesimally term, since a real life function with this term is awkwardness...it has no meaning.

    So if suppose, the area of the differentiated equation yields the desired result, then we gotta take the infinitesimally terms to one side, and take a another function...like dy/dx = z(x) or n

    This is an assertion, so I would like to confirm.
    The content of this post is not pre-calculus. Please tell us what course you are studying and what your set book is. This will allow us to diagnose your real problem.

    CB
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    aaaaa...well I actually come form india and here the education system is the worst in the world................soooo though people are qualified with a nice degree, they actually know nothing (they just mug up stuff and womit on the answer sheets).

    That's the reaons for so many 'educated' people.





    So, considering I'm doing first year engineering and qualifed 12th grade, I know nothing in reality...and that's BAD

    (and that's why I'm usually using this emoction '')

    This stuff was actually done in XII grade (XII maths is difficult than engg. here)...so I thought it to be precalcalus.

    Sorry...so do I need to post this in some other catagory?
    Last edited by dE_logics; November 5th 2008 at 08:17 PM.
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