The function f_a(x)=(ax-(1+a+a²))/(x-(1+a)) has the property that f(f(f(x)))=x for all x in the extended reals (i.e., x can be infinite as well as finite). In the graph, x can be taken to be any one of the three points on the x axis. The sides of the polygon trace out the steps of the triple compositionComponente Curricular::Educação Superior::Ciências Exatas e da Terra::Matemática