Figure 2From: Optimal control problem arises from illegal poaching of southern white rhino mathematical modelBifurcation diagram of system (2) in the p–y plane. Figure (a) is presented using \(\gamma ^{*}=0.3\), while (b) is for \(\gamma ^{*}=0.9\). Red and blue curves present \(\mathcal{E}_{3}\) and \(\mathcal{E}_{2}\), respectively. The solid curve presents the stable equilibrium, while the dotted curve is for the unstable equilibriumBack to article page