Dear all, i want to do some pharmacokinetic calculations with the convolution intergral. E.g. the input rate into the linear system is Inpfunc:=t-> a*exp(-k*t)+b*exp(-m*t); the system impulse response is Transfunc:=t->c*exp(-u*t)+d*exp(-v*t)+e*exp(-w*t); When i compute the system response to the input rate function as Respf:=int(Transfunc(t-tau)*Inpfunc(tau),tau=0..t); I do obtain a huge mess of exponentials. With the 'collect' function i collected the preexponential terms but they were still huge (abt. 4 screens full). I have tried 'factor', 'symplify' and so on but all commands