  We consider f(R) modified gravity theories for describing varying speed of
light in a spatially flat FRW model, and find some exact solutions. Also we
examine the dynamics of this model by dynamical system method assuming a
LambdaCDM background and we find some exact solutions by considering the
character of critical points of the theory in both formalisms. The behaviour of
the speed of light is obtained.

General Relativity and Quantum Cosmology