  In this paper, we have studied the dynamical aspects of some cosmological
models in an isotropic space-time within the framework of an extended gravity
theory. Two accelerating cosmological models are presented with quasi-de Sitter
(QDS) and linear combination of exponential (LCE) scale factors. The
geometrical testing mechanism has been performed and analysed. While the
results of the QDS model show a departure from the concordant $\Lambda$CDM
model, the resulting behavior of the LCE model seems to be compatible with the
$\Lambda$CDM model only at the present epoch and is incompatible in the near
past.
