The Gompertz model is dPdt=kPln(M/P)\frac{dP}{dt} = kP \ln(M/P)dtdP=kPln(M/P). What happens to the substitution v=lnPv = \ln Pv=lnP?
It becomes a Bernoulli equation.
It becomes a linear first-order equation.
It becomes non-linear.
It remains Gompertz.