Math, asked by Anonymous, 11 months ago

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If integral of dx is x

Then what is the integral of 1/dx

And what is the integral of (dx)²


Maths aryabhatta's a great question for uh pupil ‼️​


Steph0303: Integral of dx and dx^2 as mentioned in the below answers do not have any meaning.
Steph0303: This is because dx is a very small quantity. and reciprocal of a very small quantity [Like 1/dx] tends up to infinity on integrating since Integration is sum of all such dx's. So the answer turns out to be "not-defined". Maybe this can also serve as an explanation.

Coming to the second part square of a small number turns to be even smaller. So integrating that also would lead to a "not-defined" value. This is just a comment from my perspective. Your math teacher can help you out even better :)

Answers

Answered by Anonymous
40

Answer:

\large\boxed{\sf{\int dx = x + c}}

Step-by-step explanation:

To find the integral of,

\displaystyle \int dx

We can writ this as,

 = \displaystyle \int1.dx

Or, we can further write as,

 = \displaystyle \int  {x}^{0} dx

But, we know that,

  • \displaystyle \int  {x}^{n}  =  \dfrac{ {x}^{n} }{n + 1}

Therefore, we will get,

 =  \dfrac{ {x}^{0 + 1} }{0 + 1}  + c \\  \\  = x + c

Where, c is an arbitrary constant.

Now, to find the integral of 1/dx.

Actually, 1/dx doesn't have any meaning in mathematics.

It's an invalid expression or function.

So, we can't find it's integral.

Similarly, to find the integral of (dx)²

It's also, an invalid expression or function in mathematics.

So, we can't find it's integral.

Keep in mind, both of these expressions doesn't hold any meaning in mathematics.

Answered by shadowsabers03
8

Well the first statement seems totally wrong!

\begin{minipage}{10cm}``\textsf{$x$, added with a constant or not, is the integral of $\mathbf{1}$ with respect to $x$, not of $dx$.}"\end{minipage}

Because we see that,

\displaystyle\longrightarrow\sf{\int dx=\int1\ dx}

\sf{dx} exists there alone due to that \sf{1} !

\displaystyle\longrightarrow\sf{\int dx=x+c}

And if the integral constant is zero, then simply,

\displaystyle\longrightarrow\sf{\int dx=x}

And how the statement is possible?

We know the formula,

\displaystyle\longrightarrow\sf{\int x^n\ dx=\dfrac{x^{n+1}}{n+1}+c,\quad n\neq-1}

Hence we see that,

\displaystyle\longrightarrow\sf{\int dx=\int1\ dx}

\displaystyle\longrightarrow\sf{\int dx=\int x^0\ dx}

\displaystyle\longrightarrow\sf{\int dx=\dfrac{x^{0+1}}{0+1}+c}

\displaystyle\longrightarrow\sf{\int dx=\dfrac{x^{1}}{1}+c}

\displaystyle\longrightarrow\sf{\int dx=x+c}

If \sf{c=0,}

\displaystyle\longrightarrow\sf{\int dx=x}

Remember, we write some variables alone if their coefficients are 1 right?!

``\textsf{$x+y$ is the same as $1x+1y$.}"

Likewise, \displaystyle\mathsf{\int 1\ dx} is simply written as \displaystyle\mathsf{\int dx,} which is wrongly taken as "the integral of \sf{dx}" here. That's the matter!

\begin{minipage}{10cm}\displaystyle``\textsf{Integral of $x$ wrt $x$ is written symbolically as $\mathsf{\int x\ dx}$.}"\\\\``\textsf{Similarly, integral of $dx$ wrt $dx$ should be written as $\mathsf{\int dx\ dx}$.}"\end{minipage}

I just took the integral here "with respect to \sf{x,}" though the first statement ``\textsf{if the integral of $dx$ is x}" does not imply that dx is integrated about which variable, x or y or 2x\ !

By the way what does the term \sf{dx} actually mean?

The infinitesimally small sections like \sf{dx,\ dy,\ dt,\ d\theta,\ etc.} according to which the given function has to be integrated are called the integral operators.

``\textsf{Only the $\mathbf{functions}$ about the mentioned variables are able to be integrated}"

But integral operators are no longer functions. They represent the very small variation about them in the particular function as we go along it. Then how \sf{dx} can be integrated?!

Similarly, how \sf{\dfrac{1}{dx}}} and \sf{(dx)^2} can be integrated?! They could be if and only if the following functions were defined.

  • \sf{f(x)=dx}
  • \sf{f(x)=\dfrac{1}{dx},\ \ dx=0}
  • \sf{f(x)=(dx)^2}
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