El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\left(-3\right) \sin{\left(x + \frac{\pi}{6} \right)} - 2 = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \operatorname{asin}{\left(\frac{2}{3} \right)} - \frac{\pi}{6}$$
$$x_{2} = \operatorname{asin}{\left(\frac{2}{3} \right)} + \frac{5 \pi}{6}$$
Solución numérica$$x_{1} = -38.9524382749028$$
$$x_{2} = -59.4841315375774$$
$$x_{3} = -78.3336874591162$$
$$x_{4} = 74.1448972543298$$
$$x_{5} = -51.518808889262$$
$$x_{6} = -103.466428687835$$
$$x_{7} = -40.6345756160386$$
$$x_{8} = -298.245173210402$$
$$x_{9} = 9.63090684139805$$
$$x_{10} = -46.9177609232182$$
$$x_{11} = -133.200217882597$$
$$x_{12} = -21.7850196944999$$
$$x_{13} = -12950.898244529$$
$$x_{14} = 61.5785266399706$$
$$x_{15} = -2.93546377296113$$
$$x_{16} = 34.7636480701164$$
$$x_{17} = -34.3513903088591$$
$$x_{18} = -26.3860676605436$$
$$x_{19} = 72.4627599131939$$
$$x_{20} = 22.1972774557572$$
$$x_{21} = 28.4804627629368$$
$$x_{22} = 67.8617119471502$$
$$x_{23} = -82.9347354251599$$
$$x_{24} = 59.8963892988347$$
$$x_{25} = -65.767316844757$$
$$x_{26} = 86.7112678686889$$
$$x_{27} = 36.4457854112523$$
$$x_{28} = -57.8019941964415$$
$$x_{29} = 47.3300186844756$$
$$x_{30} = 3798.39164707069$$
$$x_{31} = -1.25332643182527$$
$$x_{32} = 92.9944531758685$$
$$x_{33} = -95.5011060395191$$
$$x_{34} = -210.280578909887$$
$$x_{35} = -45.2356235820824$$
$$x_{36} = 49.0121560256114$$
$$x_{37} = -15.5018343873203$$
$$x_{38} = 78.7459452203735$$
$$x_{39} = 85.0291305275531$$
$$x_{40} = -32.6692529677232$$
$$x_{41} = 91.3123158347327$$
$$x_{42} = -72.0505021519366$$
$$x_{43} = -591.872745306706$$
$$x_{44} = -84.6168727662958$$
$$x_{45} = 15.9140921485776$$
$$x_{46} = -13.8196970461844$$
$$x_{47} = 5.02985887535432$$
$$x_{48} = 23.8794147968931$$
$$x_{49} = -70.3683648108007$$
$$x_{50} = -53.2009462303978$$
$$x_{51} = 17.5962294897135$$
$$x_{52} = -97.1832433806549$$
$$x_{53} = -20.102882353364$$
$$x_{54} = -76.6515501179803$$
$$x_{55} = 80.4280825615094$$
$$x_{56} = 66.1795746060143$$
$$x_{57} = 55.295341332791$$
$$x_{58} = -64.0851795036211$$
$$x_{59} = -90.9000580734753$$
$$x_{60} = -7.53651173900485$$
$$x_{61} = -28.0682050016795$$
$$x_{62} = -9.21864908014071$$
$$x_{63} = 11.3130441825339$$
$$x_{64} = 3.34772153421846$$
$$x_{65} = -89.2179207323395$$
$$x_{66} = 41.046833377296$$
$$x_{67} = 99.2776384830481$$
$$x_{68} = 30.1626001040727$$
$$x_{69} = 53.6132039916552$$
$$x_{70} = 97.5955011419123$$
$$x_{71} = 42.7289707184318$$