El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\sin{\left(\frac{2 x}{3} \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 0$$
$$x_{2} = \frac{3 \pi}{2}$$
Solución numérica$$x_{1} = 14.1371669411541$$
$$x_{2} = -18.8495559215388$$
$$x_{3} = -37.6991118430775$$
$$x_{4} = 89.5353906273091$$
$$x_{5} = -23.5619449019235$$
$$x_{6} = -56.5486677646163$$
$$x_{7} = 84.8230016469244$$
$$x_{8} = 61.261056745001$$
$$x_{9} = 42.4115008234622$$
$$x_{10} = -4.71238898038469$$
$$x_{11} = 94.2477796076938$$
$$x_{12} = 0$$
$$x_{13} = -42.4115008234622$$
$$x_{14} = -75.398223686155$$
$$x_{15} = 51.8362787842316$$
$$x_{16} = 47.1238898038469$$
$$x_{17} = 75.398223686155$$
$$x_{18} = 28.2743338823081$$
$$x_{19} = -80.1106126665397$$
$$x_{20} = 32.9867228626928$$
$$x_{21} = -98.9601685880785$$
$$x_{22} = -47.1238898038469$$
$$x_{23} = -32.9867228626928$$
$$x_{24} = 18.8495559215388$$
$$x_{25} = -94.2477796076938$$
$$x_{26} = -61.261056745001$$
$$x_{27} = 56.5486677646163$$
$$x_{28} = -28.2743338823081$$
$$x_{29} = 4.71238898038469$$
$$x_{30} = -9.42477796076938$$
$$x_{31} = -2148.84937505542$$
$$x_{32} = -51.8362787842316$$
$$x_{33} = 23.5619449019235$$
$$x_{34} = -14.1371669411541$$
$$x_{35} = 98.9601685880785$$
$$x_{36} = 80.1106126665397$$
$$x_{37} = 37.6991118430775$$
$$x_{38} = 70.6858347057703$$
$$x_{39} = 9.42477796076938$$
$$x_{40} = 65.9734457253857$$
$$x_{41} = -89.5353906273091$$
$$x_{42} = -70.6858347057703$$
$$x_{43} = -65.9734457253857$$
$$x_{44} = -84.8230016469244$$