El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\sin{\left(x \right)} + 3 \cos{\left(x \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \operatorname{atan}{\left(3 \right)}$$
Solución numérica$$x_{1} = 55.299621992218$$
$$x_{2} = -95.496825380092$$
$$x_{3} = -42.0897502690656$$
$$x_{4} = -73.5056768049635$$
$$x_{5} = 262.644737129144$$
$$x_{6} = -45.2313429226554$$
$$x_{7} = 1.89254688119154$$
$$x_{8} = 64.7243999529874$$
$$x_{9} = 52.1580293386282$$
$$x_{10} = -82.9304547657329$$
$$x_{11} = -89.2136400729125$$
$$x_{12} = 74.1491779137568$$
$$x_{13} = 42.7332513778588$$
$$x_{14} = 96.1403264888853$$
$$x_{15} = -35.806564961886$$
$$x_{16} = -70.3640841513737$$
$$x_{17} = 61.5828072993976$$
$$x_{18} = 23.8836954563201$$
$$x_{19} = 45.8748440314486$$
$$x_{20} = 33.3084734170895$$
$$x_{21} = 89.8571411817058$$
$$x_{22} = -98.6384180336818$$
$$x_{23} = 39.5916587242691$$
$$x_{24} = -26.3817870011166$$
$$x_{25} = -29.5233796547064$$
$$x_{26} = -76.6472694585533$$
$$x_{27} = 11.3173248419609$$
$$x_{28} = 99.2819191424751$$
$$x_{29} = -629.567576490357$$
$$x_{30} = 58.4412146458078$$
$$x_{31} = -38.9481576154758$$
$$x_{32} = 36.4500660706793$$
$$x_{33} = 20.7421028027303$$
$$x_{34} = 49.0164366850384$$
$$x_{35} = -13.8154163867574$$
$$x_{36} = -60.9393061906043$$
$$x_{37} = 5.03413953478133$$
$$x_{38} = 17.6005101491405$$
$$x_{39} = -86.0720474193227$$
$$x_{40} = -32.6649723082962$$
$$x_{41} = -20.098601693937$$
$$x_{42} = 80.4323632209364$$
$$x_{43} = -92.3552327265023$$
$$x_{44} = -114.346381301631$$
$$x_{45} = 8.17573218837112$$
$$x_{46} = -7.53223107957784$$
$$x_{47} = -16.9570090403472$$
$$x_{48} = -10.6738237331676$$
$$x_{49} = -51.5145282298349$$
$$x_{50} = 71.007585260167$$
$$x_{51} = -23.2401943475268$$
$$x_{52} = -48.3729355762452$$
$$x_{53} = 14.4589174955507$$
$$x_{54} = 77.2907705673466$$
$$x_{55} = -1.24904577239825$$
$$x_{56} = -79.7888621121431$$
$$x_{57} = -64.0808988441941$$
$$x_{58} = -67.2224914977839$$
$$x_{59} = -54.6561208834247$$
$$x_{60} = -4.39063842598805$$
$$x_{61} = 67.8659926065772$$
$$x_{62} = 27.0252881099099$$
$$x_{63} = 30.1668807634997$$
$$x_{64} = -1226.47018067242$$
$$x_{65} = 86.715548528116$$
$$x_{66} = 83.5739558745262$$
$$x_{67} = 92.9987338352955$$
$$x_{68} = -57.7977135370145$$