Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit ode2('diff(N,t)= 4.0644e-6*N*(66750-N), N,t); followed by solve(%,N); also gives a very disappointing answer. Is there a simple way to make maxima solve this (rather simple) equation? Yours, Poul Riis