Figure 6

Positive equilibrium varying β ₂ . The coordinates of the positive equilibrium points varying β₂. In (a) we show the coordinates of the small equilibrium point ${\bar{Q}}_{<}^{*}$, and in (b), of the big equilibrium point ${\bar{Q}}_{>}^{*}$. The small root T_<increases, while the big one T_> decreases up to ${\beta }_2^c$, at which T_<= T_<, and then f(T) = g(T) does not have positive solution. The scales of vertical and horizontal axes must be multiplied by the factors shown in the legends to obtain the actual values.