El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$2 \sin{\left(3 x \right)} + 3 \cos{\left(2 x \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución numérica$$x_{1} = -71.8208658307018$$
$$x_{2} = -44.4180623521205$$
$$x_{3} = 38.6144314610242$$
$$x_{4} = 53.8428403128899$$
$$x_{5} = -2.7058274517264$$
$$x_{6} = -79.4551359576915$$
$$x_{7} = 46.2085701859003$$
$$x_{8} = 97.825137463147$$
$$x_{9} = 33.6421995715411$$
$$x_{10} = -82.117174195198$$
$$x_{11} = 8.50945834282275$$
$$x_{12} = 32.3312461538446$$
$$x_{13} = -68.1997187610288$$
$$x_{14} = 72.6923962344286$$
$$x_{15} = 49.8297172555733$$
$$x_{16} = -34.1217539876243$$
$$x_{17} = -27.8385686804447$$
$$x_{18} = -17.9342363035921$$
$$x_{19} = 83.9076820289778$$
$$x_{20} = -31.8516917377613$$
$$x_{21} = -35.4728388074344$$
$$x_{22} = -10.340097578716$$
$$x_{23} = 90.1908673361574$$
$$x_{24} = -75.8339888880184$$
$$x_{25} = -38.1348770449409$$
$$x_{26} = -69.5508035808388$$
$$x_{27} = 2.22627303564316$$
$$x_{28} = 26.048060846665$$
$$x_{29} = 100.09519971301$$
$$x_{30} = -54.3223947289731$$
$$x_{31} = -98.3046918792302$$
$$x_{32} = -55.6333481466696$$
$$x_{33} = -21.5553833732652$$
$$x_{34} = -99.6156452969267$$
$$x_{35} = 19.7648755394854$$
$$x_{36} = -61.9165334538492$$
$$x_{37} = 284.969611858725$$
$$x_{38} = 62.3960878699325$$
$$x_{39} = 82.5967286112813$$
$$x_{40} = 41.2764696985307$$
$$x_{41} = -78.1040511378814$$
$$x_{42} = -11.6510509964125$$
$$x_{43} = -36.7837922251309$$
$$x_{44} = 107.72946984$$
$$x_{45} = -80.766089375388$$
$$x_{46} = 18.4137907196754$$
$$x_{47} = -52.9713099091631$$
$$x_{48} = 16.1437284698124$$
$$x_{49} = 93.8120144058304$$
$$x_{50} = -88.4003595023776$$
$$x_{51} = -92.0215065720506$$
$$x_{52} = -15.2721980660856$$
$$x_{53} = -4.05691227153643$$
$$x_{54} = 96.474052643337$$
$$x_{55} = -820.871002204883$$
$$x_{56} = 22.4269137769919$$
$$x_{57} = -25.5685064305817$$
$$x_{58} = 9.86054316263277$$
$$x_{59} = 76.3135433041017$$
$$x_{60} = 87.5288290986508$$
$$x_{61} = 70.0303579969221$$
$$x_{62} = -46.6881246019835$$
$$x_{63} = -0.435765201863393$$
$$x_{64} = 63.7471726897425$$
$$x_{65} = 43.5465319483937$$
$$x_{66} = -48.0392094217935$$
$$x_{67} = -85.738321264871$$
$$x_{68} = 5.84742010531619$$
$$x_{69} = 3.57735785545319$$
$$x_{70} = -24.2174216107717$$
$$x_{71} = 56.1129025627529$$
$$x_{72} = 39.9253848787207$$
$$x_{73} = 28.7100990841715$$
$$x_{74} = 60.1260256200695$$
$$x_{75} = -41.7560241146139$$
$$x_{76} = 85.2587668487878$$
$$x_{77} = -65.5376805235223$$
$$x_{78} = 66.409210927249$$
$$x_{79} = -154.853359643846$$
$$x_{80} = 12.1306054124958$$
$$x_{81} = 52.4917554930799$$