Date: Feb 13, 2011 12:57 AM
Author: Chaitanya Vichare
Subject: Problem with inverse laplace

Hi all 
I am trying to get inverse laplace of following expression
>syms s
>>Ys3 = (80000*s^2 + 400000*s)/(s^5 + 30*s^4 + 395300*s^3 + 11850000*s^2 + 202500000*s);

so I did in the following way:
yt3 = ilaplace(Ys3);

I am getting the following answer! I expect a numeric value as a answer.
>>yt3 = sum((400000*exp(r3*t) + 80000*r3*exp(r3*t))/(4*r3^3 + 90*r3^2 + 790600*r3 + 11850000), r3 in RootOf(s3^4 + 30*s3^3 + 395300*s3^2 + 11850000*s3 + 202500000, s3))

r3 and s3 are not defined by me!

Please help to understand this expression.
Thank you