El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\left(\cos{\left(x \right)} + 1\right) - \frac{3}{4 \cos{\left(x \right)}} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = \frac{\pi}{3}$$
$$x_{2} = \frac{5 \pi}{3}$$
Solución numérica$$x_{1} = 36.6519142918809$$
$$x_{2} = -24.0855436775217$$
$$x_{3} = -137.182879206754$$
$$x_{4} = 32.4631240870945$$
$$x_{5} = 26.1799387799149$$
$$x_{6} = -3262.0203719774$$
$$x_{7} = -7.33038285837618$$
$$x_{8} = 49.2182849062401$$
$$x_{9} = 17.8023583703422$$
$$x_{10} = -95.2949771588904$$
$$x_{11} = -68.0678408277789$$
$$x_{12} = 19.8967534727354$$
$$x_{13} = -26.1799387799149$$
$$x_{14} = -93.2005820564971$$
$$x_{15} = -765.501409924713$$
$$x_{16} = 158.126830230686$$
$$x_{17} = 80.634211442138$$
$$x_{18} = 57.5958653158129$$
$$x_{19} = 24.0855436775217$$
$$x_{20} = -19.8967534727354$$
$$x_{21} = 95.2949771588904$$
$$x_{22} = -13.6135681655558$$
$$x_{23} = -30.3687289847013$$
$$x_{24} = 5.23598775598299$$
$$x_{25} = -45.0294947014537$$
$$x_{26} = -93.2005820564972$$
$$x_{27} = -11.5191730631626$$
$$x_{28} = -74.3510261349584$$
$$x_{29} = -57.5958653158129$$
$$x_{30} = 86.9173967493176$$
$$x_{31} = 76.4454212373516$$
$$x_{32} = -17.8023583703422$$
$$x_{33} = 89.0117918517108$$
$$x_{34} = -55.5014702134197$$
$$x_{35} = 63.8790506229925$$
$$x_{36} = 68.0678408277789$$
$$x_{37} = 101.57816246607$$
$$x_{38} = -99.4837673636768$$
$$x_{39} = -49.2182849062401$$
$$x_{40} = -63.8790506229925$$
$$x_{41} = 61.7846555205993$$
$$x_{42} = 1062.90551446455$$
$$x_{43} = 74.3510261349584$$
$$x_{44} = -70.162235930172$$
$$x_{45} = 70.162235930172$$
$$x_{46} = -61.7846555205993$$
$$x_{47} = 30.3687289847013$$