The inverse of this laplace domain: laplaceinverse(&#873

[cedance]

laplace inverse?

hi,

i need to know the inverse of this laplace domain variable badly!

laplaceinverse(√(1+s)) = ?????

i experimented with matlab and got the same thing as the inverse. it is not calculating the ivnerse and displaying the result in the time domain.. is there an inverse existing for this function if so wat is it? pls anyone help me getting the result!!!

matlab command:

syms s
f1 = sqrt(1+s)
ilaplace(f1)
ans =

ilaplace(√1+s, s, t)

it gives back the same result like this!!!

Thank u very much! i have been wanting this for many days! dint know abt the power of mathematica!!! wuill have it in mind hereafter! GR8...

/cedance

 

[chirkut_iis]

Re: laplace inverse?

I got this from Mathematica...there's nothing that beats it at Symbolic comp!

C

P.S. I couldn't get it to give proper latex o/p or MathML , so had to post the gifs.

 

[cedance]

Re: laplace inverse?

I got this from Mathematica...there's nothing that beats it at Symbolic comp!
C
P.S. I couldn't get it to give proper latex o/p or MathML , so had to post the gifs.

hi,

i checked the value of sqrt(1+s) with mathematica and have two more things to be asked!

1) how do we check the validity of the result obtained... i mean, is htere any other softwrae by which i can cross check. i knew taking the laplace of this function would give back again the same incase it s right.. but i wanted to do it using another software, but when tried in matlab it dint give me the result... thou i dont doubt the efficiency of mathematica, i wanted to be double sure..

2) i also wanted the laplace inverse of exp(sqrt(1+s)). mathematica is not giving the result for this function. but it gives the result for exp(-sqrt(1+s)). can u help me in getting the inverse foir that too?

/cedance

 

[chirkut_iis]

Re: laplace inverse?

I think one way to cross-check is to compare numerically calculated and analytically obtained transform plots. It so happens that sometimes finding analytical inverses of laplace transforms is a formidable task. Then numerical solution remains the only other alternative.
So, the answer to your question could be
1) check numerical output and compare with analytical one in region of interest.
2) I will try to calculate myself and will let you know if I get an answer. In the meanwhile you might have to be content with the numerical o/p in the domain of interest. Check this out for the same...
https://library.wolfram.com/infocenter/MathSource/2691/

 

[spauls]

Re: laplace inverse?

U can use Series method(Taylor or Maclurin) and made a generic algorithm for that, dir it may cause problem.
I have algo , but i cant put publically ,

 

[v_naren]

Re: laplace inverse?

hi,

i need to know the inverse of this laplace domain variable badly!

laplaceinverse(√(1+s)) = ?????

i experimented with matlab and got the same thing as the inverse. it is not calculating the ivnerse and displaying the result in the time domain.. is there an inverse existing for this function if so wat is it? pls anyone help me getting the result!!!

matlab command:

syms s
f1 = sqrt(1+s)
ilaplace(f1)
ans =

ilaplace(√1+s, s, t)

it gives back the same result like this!!!

Thank u very much! i have been wanting this for many days! dint know abt the power of mathematica!!! wuill have it in mind hereafter! GR8...

regards,
arunmit168.

I think answer is

\[-{\frac{1}{2t\sqrt{\pi t}}}e^{-t}\]

If the symbols dont appear correctly please type this https://www.edaboard.com/h**p://tryton.plocman.pl/gula-cgi/mimetex/mimetex.cgi?3$-{\frac{1}{2t\sqrt{\pi t}}}e^{-t}