El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$5 \cos^{3}{\left(x \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = \frac{\pi}{2}$$
$$x_{2} = \frac{3 \pi}{2}$$
Solución numérica$$x_{1} = 36.128317789764$$
$$x_{2} = 23.5619763533234$$
$$x_{3} = -89.5354410428862$$
$$x_{4} = 58.1194603256925$$
$$x_{5} = -7.85396939058216$$
$$x_{6} = 14.1371748405436$$
$$x_{7} = 51.8363261592826$$
$$x_{8} = -58.1194276545353$$
$$x_{9} = 86.3937628262857$$
$$x_{10} = -45.5531401844306$$
$$x_{11} = -42.4114638604687$$
$$x_{12} = -67.5442906223714$$
$$x_{13} = -95.8185603030962$$
$$x_{14} = 48.6946439323886$$
$$x_{15} = -51.8362625267018$$
$$x_{16} = -1.57083925518957$$
$$x_{17} = -29.8451152214988$$
$$x_{18} = 95.818627417042$$
$$x_{19} = -14.1371260033657$$
$$x_{20} = 20.4203112367381$$
$$x_{21} = -80.1105785507599$$
$$x_{22} = 73.8274768053124$$
$$x_{23} = 92.6770059000324$$
$$x_{24} = 70.6858302611407$$
$$x_{25} = 7.85402475701276$$
$$x_{26} = 80.1106035284868$$
$$x_{27} = 1.57080273224359$$
$$x_{28} = -23.5619897288019$$
$$x_{29} = 64.4026122770508$$
$$x_{30} = -73.827410994311$$
$$x_{31} = 29.8451754771722$$
$$x_{32} = -20.4203505482106$$
$$x_{33} = -36.1282768063468$$
$$x_{34} = 45.5531567451367$$
$$x_{35} = 42.4114617473496$$