Paper 4, Section II, D

Dynamical Systems
Part II, 2010

Let I=[0,1]I=[0,1] and consider continuous maps F:IIF: I \rightarrow I. Give an informal outline description of the two different bifurcations of fixed points of FF that can occur.

Illustrate your discussion by considering in detail the logistic map

F(x)=μx(1x),F(x)=\mu x(1-x),

for μ(0,1+6]\mu \in(0,1+\sqrt{6}].

Describe qualitatively what happens for μ(1+6,4]\mu \in(1+\sqrt{6}, 4].

[You may assume without proof that

xF2(x)=x(μxμ+1)(μ2x2μ(μ+1)x+μ+1)x-F^{2}(x)=x(\mu x-\mu+1)\left(\mu^{2} x^{2}-\mu(\mu+1) x+\mu+1\right)