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Integration of exp(az)*sigma(tto)*dz ??
Posted:
Dec 1, 1996 11:32 PM


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 email, since I don't read this newsgroup everyday.
Thanks in advance
Farzad



