Hello you all, I have to solve the following integration, who can help me or give me some hints?
I(t) = A * Integral(from z=zo until oo) exp(-a*z) * sigma(t - to) dz
Where: zo is the lower and oo (infinite) is the upper integral limit A, zo and a are constants to = (z - zo)^2 / D, with D as a constant sigma is a step function and is defined: sigma = 0 for t<to sigma = 1 for t>=to
My actual problem is to find a way to integrate the step function sigma. Is there any possiblities to approximate it to a mathematical function. Or is there any rule for its integration that I am not aware of it. I have already looked in some Math books but I didn't find it.
PS1: Please let me know whether there are also other newsgroups dealing with these problems. Ps2: Please send me your responses via e-mail, since I don't read this newsgroup everyday.