El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\operatorname{acos}^{3}{\left(\frac{x}{3} \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 3$$
Solución numérica$$x_{1} = 3.00000000900027$$
$$x_{2} = 2.99999999950801$$
$$x_{3} = 2.99999999870828$$
$$x_{4} = 3.00000001252141$$
$$x_{5} = 3.00000000022804$$
$$x_{6} = 3.0000000027942$$
$$x_{7} = 2.99999999991785$$
$$x_{8} = 2.99999999850633$$
$$x_{9} = 3.00000000016904$$
$$x_{10} = 3.00000000009657$$
$$x_{11} = 3.00000000020682$$
$$x_{12} = 3.00000000008136$$
$$x_{13} = 3.00000000021366$$
$$x_{14} = 3.00000000628064$$
$$x_{15} = 3.00000001407535$$
$$x_{16} = 3.00000000523944$$
$$x_{17} = 3.00000000282715$$
$$x_{18} = 3.00000000281721$$
$$x_{19} = 3.00000000251654$$
$$x_{20} = 2.99999999977739$$
$$x_{21} = 3.00000000498321$$
$$x_{22} = 3.00000000273645$$
$$x_{23} = 3.00000000023102$$
$$x_{24} = 3.00000000170794$$
$$x_{25} = 3.00000000945632$$
$$x_{26} = 3.00000001018833$$
$$x_{27} = 3.0000000112129$$
$$x_{28} = 3.00000000000235$$
$$x_{29} = 3.00000000016548$$
$$x_{30} = 3.00000000453742$$
$$x_{31} = 2.99999999997554$$
$$x_{32} = 2.99999999916029$$
$$x_{33} = 3.00000001580597$$
$$x_{34} = 3.00000000195897$$
$$x_{35} = 2.99999999956895$$
$$x_{36} = 2.99999999950696$$
$$x_{37} = 2.99999999880108$$