We study inflation in a model with constant second slow-roll parameter
η. In this case, the Hubble expansion rate equation has analytical
solutions describing four possible, nontrivial inflation scenarios. The
evolution of the inflaton governed by a tachyon field is studied in the
framework of the standard and Randall-Sundrum II cosmology. The attractor
behavior of the solution is briefly demonstrated. Finally, the calculated
values of the parameters ns​ and r are compared with observational
data