276 reputation
114
bio website ziga-lausegger.netau.net/…
location Slovenia
age 28
visits member for 2 years, 7 months
seen Nov 26 '13 at 13:11

I love to program and crosscompile baremetal C programs for ARM based microcontrollers, I love physics and i love writing science documents/books in LaTeX. It amazes me how physics is connecting all science and is helping mathematics to evolve. In order for science profession to comunicate on a high level i advise everyone to use Linux, LaTeX and a good vector imaging program like Inkscape.


Aug
12
revised Some exponential integrals - I need algebraical solution besides my graphical one
added 248 characters in body
Aug
12
asked Some exponential integrals - I need algebraical solution besides my graphical one
Aug
9
accepted Need some algebra explaination for hyperbolic sinus
Aug
9
asked Need some algebra explaination for hyperbolic sinus
Aug
2
accepted Trigonometric functions
Aug
2
comment Trigonometric functions
Yes. I need to know how to get RHS out of LHS. I tried to use the double angle trigonometric identity and it only got more complicated...
Aug
2
asked Trigonometric functions
Aug
2
comment Short integral question
I think i understand everything now exept this: $\left.-\pi\int\limits_0^\infty(-2r\,dr)e^{-r^2}=-\pi e^{-r^2}\right|_0^\infty$ How do you do this?
Aug
2
comment Short integral question
@DonAntonio but i am using a Google Chrome it is the best :)
Aug
1
accepted Short integral question
Aug
1
comment Short integral question
I upvoted all of you (I hope it helps). This wouldn't be the first time this happened. This page is somehow bugged it seems.
Aug
1
comment Short integral question
Oh i did ... But i didn't know. It happened because this page is jumping up and down while those advertisments are loading. I fixed the downvote.
Aug
1
comment Short integral question
I downvoted noone ...
Aug
1
comment Short integral question
Thank you for this explaination and I am sorry but this $e^x$ function ... I hate it at the moment. Really. Maybee I ll have more questions.
Aug
1
comment Short integral question
But $x\neq y$ :((( It never will be. I don't understand...
Aug
1
comment Short integral question
So I calculated $\int xe^{-x^2/a} dx$ in Wolfram alpha and I can see that the chain rule has been aplied corectly ( wolframalpha.com/input/?i=int+x*e%5E%7B-x%5E2%2Fa%7D ) because what i got is $-\frac{a}{2}e^{-x^2/a}$. So why wouldn't a chain rule work if I only remove $x$? Mathematics fails?
Aug
1
comment Short integral question
This is wrong: $\left(\int\limits_{-\infty}^\infty e^{-x^2}dx\right)^2=\int\limits_{-\infty}^\infty e^{-x^2}dx\int\limits_{-\infty}^\infty e^{-y^2}dy$ How come you use $y$ in place of $x$... I cant just write 2x = 2g...
Aug
1
comment Short integral question
OMG i wrote my equation a bit wrong and now the "X" mark to edit it is behind the right margin of this webpage. I can't edit... ADMIN PLEASE HELP.
Aug
1
comment Short integral question
I mean we usualy did like this: $\frac{d}{dx}\sin\left(x^2\right) = \underbrace{\cos\left(x^2\right)}_{\frac{d}{dx}\sinqleft(x^2\right)} \cdot \underbrace{2x}_{\rlap{\text{derivative of what is inside the bracket}}}$ The Wolfram alpha confirms it wolframalpha.com/input/?i=d%2Fdx%20%5Csin(x%5E2)&t=crmtb01
Aug
1
comment Short integral question
But there is a rule that $d/dx ~[f(x)] = df(x)/dx \cdot dx/dx$ ... Why do we have such a rule if it doesnt apply for ALL the functions including exponential? Can anyone provide me a solution to this case?