El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\frac{1}{\log{\left(\sin{\left(x \right)} + 1 \right)}} + \frac{\sin{\left(2 x \right)}}{\cos{\left(x \right)} + 1} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución numérica$$x_{1} = 58.6124295473767$$
$$x_{2} = 77.4619854689155$$
$$x_{3} = -54.4849059818559$$
$$x_{4} = 54.8972985721627$$
$$x_{5} = 67.4636691865219$$
$$x_{6} = 39.7628736258379$$
$$x_{7} = -1.65136919245356$$
$$x_{8} = 27.1965030114788$$
$$x_{9} = -20.5009251139923$$
$$x_{10} = 8.34694708994001$$
$$x_{11} = 64.8956148545563$$
$$x_{12} = -83.3327781857882$$
$$x_{13} = -16.7857941387783$$
$$x_{14} = -33.0672957283515$$
$$x_{15} = -51.9168516498902$$
$$x_{16} = 61.1804838793423$$
$$x_{17} = -79.6176472105742$$
$$x_{18} = 20.9133177042992$$
$$x_{19} = 92.5964104152402$$
$$x_{20} = -26.7841104211719$$
$$x_{21} = -10.5026088315988$$
$$x_{22} = 29.7645573434444$$
$$x_{23} = -14.2177398068127$$
$$x_{24} = 98.8795957224198$$
$$x_{25} = -23.0689794459579$$
$$x_{26} = 46.0460589330175$$
$$x_{27} = 83.7451707760951$$
$$x_{28} = 48.6141132649831$$
$$x_{29} = 52.3292442401971$$
$$x_{30} = 42.3309279578035$$
$$x_{31} = -89.6159634929678$$
$$x_{32} = 14.6301323971196$$
$$x_{33} = -39.3504810355311$$
$$x_{34} = -58.2000369570698$$
$$x_{35} = 36.047742650624$$
$$x_{36} = -70.766407571429$$
$$x_{37} = 71.1788001617359$$
$$x_{38} = 23.4813720362648$$
$$x_{39} = -35.6353500603171$$
$$x_{40} = 17.1981867290852$$
$$x_{41} = -92.1840178249334$$
$$x_{42} = 73.7468544937015$$
$$x_{43} = -77.0495928786086$$
$$x_{44} = -41.9185353674967$$
$$x_{45} = -73.3344619033946$$
$$x_{46} = 86.3132251080606$$
$$x_{47} = -85.9008325177538$$
$$x_{48} = -60.7680912890354$$
$$x_{49} = 2.06376178276042$$
$$x_{50} = 80.0300398008811$$
$$x_{51} = -7.93455449963314$$
$$x_{52} = -45.6336663427107$$
$$x_{53} = -4.21942352441916$$
$$x_{54} = -64.4832222642494$$
$$x_{55} = 4.63181611472603$$
$$x_{56} = 33.4796883186584$$
$$x_{57} = 10.9150014219056$$
$$x_{58} = -48.2017206746763$$
$$x_{59} = -29.3521647531375$$
$$x_{60} = 96.3115413904542$$
$$x_{61} = 90.0283560832746$$
$$x_{62} = -98.467203132113$$
$$x_{63} = -95.8991488001474$$
$$x_{64} = -67.051276596215$$