  Two accelerating cosmological models are presented in symmetric teleparallel
$f(Q)$ gravity, $Q$ be the non-metricity. The models are constructed based on
the assumptions of two different functional forms of $f(Q)$ and a dynamically
changing nature of the deceleration parameter that shows transition at
$t=2n\pm\sqrt{\frac{4n^2+1}{3}}$, $n$ being a positive constant. In both the
models, the equation of state parameter for the dark energy in $f(Q)$ gravity
becomes a dynamical quantity and crosses the phantom divide line. The violation
of the strong energy condition and the null energy condition at late times are
also established. In addition, the dynamical system analysis has been performed
and three critical points in each model are identified. In each model, at least
one stable node has been observed. To strengthen further, the stability
analysis using homogeneous linear perturbations has been performed to ensure
the stability of the models.
