Note that \( f(x) \) is odd and rational of degree asymptotically 1 (since \( \deg N - \deg D = 3 - 2 = 1 \)), so \( f(f(x)) \) is a composition of rational functions of degrees 1 and 1, but numerator degree ≈ 3 + 2 = 5? Actually, degree of numerator in \( f(f(x)) \) is \( \deg(N^3) = 9 \), and denominator degree \( D(N^2 + D^2) \) is degree \( 2(5) = 10 \)? Wait, more carefully: - Portal da Acústica