Home › Blogs › sungyg's blog

Inverse Laplace xform of exponential function with summation

Posted on 2006-10-05 21:05 By sungyg (Maple Rating 1 47)
Categories:

Hello!

I got a trouble to get the answer of following
exponential function with summation.
I expect that the answer should be "Heaviside" forms.
However, the maple software does not go further.

restart;
assume(i::posint,n::posint,s::complex);
eq1:=sum((-1)^i*exp(-s*T[i])/s,i = 1..n);
inttrans[invlaplace](eq1,s,t) assuming T[i]>0,T[i+1]>T[i];

I am a novice for maple. Is there any procedure routine?
Please tell me about it.

Thanks.

Y-G Sung
sungyg@chosun.ac.kr

Comments

unidentified constants

Comment on 2006-10-06 16:43 from Mariner (Maple Rating 4 562)

Maple can't solve your eq1, unless you tell it the values of the constants T[1] .. T[n].

Hope this helps.

J. Tarr

alec's picture

A workaround

Comment on 2006-10-14 17:00 from alec (Maple Rating 4 1606)

A workaround is 

applyop(inttrans[invlaplace],1,eq1,s,t) assuming T[i]>0;

                  sum((-1)^i*Heaviside(t-T[i]),i = 1 .. n)

The assume command after the restart command in your code is not necessary.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
}