Dear Spoolx,
This integration could not be found using elementary functions. See Wolfram Mathematica Online Integrator
Question 1
First thing I did was attempt integration by parts
Using the formula
I come up with
Here is where I get stuck with the integration, I think I can move the
up top and make it
So I am left with
Above is Supposed to be a negative 2, but couldnt find the code for it.
So if I use u sub
The 3 I can handle but not sure what to do about the fact that my exponent is negative, and my dU has a positive.
Any help?
Thanks
Rich
Dear Spoolx,
This integration could not be found using elementary functions. See Wolfram Mathematica Online Integrator
But... parts once more takes you to
which is the ExpIntegralEi - Wolfram Mathematica 8 Documentation the exponential integral of 1/x.
http://www.wolframalpha.com/input/?i...281%2Fx%29%2Fx
So you can use parts to arrive at Wolfram's result, even though the special function is switching off the 'show steps' option that Wolfram usually offers.
Just in case a picture helps...
... where (key in spoiler) ...
Spoiler:
(But, oh dear, the new MHF page layout isn't friendly to wide diagrams.)
_________________________________________
Don't integrate - balloontegrate!
Balloon Calculus; standard integrals, derivatives and methods
Balloon Calculus Drawing with LaTeX and Asymptote!
Hey! Thats a suprise. The exponential integral is defined as . Therefore you are correct. The answer could be obtained easily. And thank you very much for pointing that, I learnt something new.
To Spoolx,
Sorry if I confused you in my previous post. When I saw the Ei abbreviation in wolfram thought it was something which we cant obtain. The problem is correct.
Well, this is incorrect. You use 'integration by parts' to integrate which, with this u and dv, would be . What you have is and the integration by parts formula does not apply.
Using the formula
I come up with
Here is where I get stuck with the integration, I think I can move the
up top and make it
So I am left with
Above is Supposed to be a negative 2, but couldnt find the code for it.
So if I use u sub
The 3 I can handle but not sure what to do about the fact that my exponent is negative, and my dU has a positive.
Any help?
Thanks
Rich