In Fig. 2, we use the same parameters and initial values as before with = 05, = 012 and = 01. Fig.
2(a) shows that the number of potential smokers decreases at …rst, then it approaches ¤. Fig. 2(b) shows that the
number of smokers increases at …rst, then it decreases slightly and approaches ¤. In Fig. 2(c), temporary quitters
decrease at …rst, after that they increase and approach ¤ In Fig. 2(d), permanent quitters increase and approach
¤. We see from Fig. 2 that for any initial value, the solution curves tend to the equilibrium ¤, when > and
> Hence, model 2 is locally asymptotically stable about ¤ for the above set of parameters..