why can't mma find this limit ??

*To*: mathgroup at smc.vnet.net*Subject*: [mg2418] why can't mma find this limit ??*From*: Christian.Jost at epc.u-psud.fr (Christian Jost)*Date*: Sun, 5 Nov 1995 16:05:37 -0500*Organization*: Universite Paris-Sud XI

I have the simple function n[t_]=3DK n0/((K-n0) Exp[-r t] + n0) (the solution of logistic growth dN/dt=3Dr (1-N/K) N ) In the limit t=3D0 this function is n0 and mma can calculate this. The li= mit for Inifinity is obviously K, but mathematica returns the limit unevaluated In: Limit[n[t],t->Infinity] Out: Limit[(K*n0)/((K - n0)/E^(r*t) + n0),=20 =20 t -> DirectedInfinity[1]] Any idea why? Is there a package that helps for such problems? Thanks, Christian. --=20 Christian Jost, Universit=E9 Paris-Sud XI, Orsay, France jost at psisun.u-psud.fr