El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$2 \cos{\left(x - \frac{\pi}{3} \right)} - 1 = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 0$$
$$x_{2} = \frac{2 \pi}{3}$$
Solución numérica$$x_{1} = -79.5870138909414$$
$$x_{2} = -62.8318530717959$$
$$x_{3} = 87.9645943005142$$
$$x_{4} = 27.2271363311115$$
$$x_{5} = 31.4159265358979$$
$$x_{6} = -56.5486677646163$$
$$x_{7} = 69.1150383789755$$
$$x_{8} = 20.943951023932$$
$$x_{9} = -37.6991118430775$$
$$x_{10} = -81.6814089933346$$
$$x_{11} = 33.5103216382911$$
$$x_{12} = -92.1533845053006$$
$$x_{13} = 2.0943951023932$$
$$x_{14} = -161.268422884276$$
$$x_{15} = -12.5663706143592$$
$$x_{16} = -4.18879020478639$$
$$x_{17} = -54.4542726622231$$
$$x_{18} = 12.5663706143592$$
$$x_{19} = -87.9645943005142$$
$$x_{20} = 8.37758040957278$$
$$x_{21} = -98.4365698124802$$
$$x_{22} = -100.530964914873$$
$$x_{23} = 83.7758040957278$$
$$x_{24} = 77.4926187885482$$
$$x_{25} = -94.2477796076938$$
$$x_{26} = 96.342174710087$$
$$x_{27} = 6.28318530717959$$
$$x_{28} = -69.1150383789755$$
$$x_{29} = 0$$
$$x_{30} = 108.908545324446$$
$$x_{31} = -41.8879020478639$$
$$x_{32} = -50.2654824574367$$
$$x_{33} = -25.1327412287183$$
$$x_{34} = 18.8495559215388$$
$$x_{35} = -18.8495559215388$$
$$x_{36} = -29.3215314335047$$
$$x_{37} = 14.6607657167524$$
$$x_{38} = 90.0589894029074$$
$$x_{39} = 37.6991118430775$$
$$x_{40} = -43.9822971502571$$
$$x_{41} = 39.7935069454707$$
$$x_{42} = -236.666646570431$$
$$x_{43} = -6.28318530717959$$
$$x_{44} = 64.9262481741891$$
$$x_{45} = 43.9822971502571$$
$$x_{46} = -60.7374579694027$$
$$x_{47} = 56.5486677646163$$
$$x_{48} = -67.0206432765823$$
$$x_{49} = 58.6430628670095$$
$$x_{50} = 25.1327412287183$$
$$x_{51} = 52.3598775598299$$
$$x_{52} = 75.398223686155$$
$$x_{53} = 81.6814089933346$$
$$x_{54} = -75.398223686155$$
$$x_{55} = -85.870199198121$$
$$x_{56} = 100.530964914873$$
$$x_{57} = 71.2094334813686$$
$$x_{58} = -31.4159265358979$$
$$x_{59} = -16.7551608191456$$
$$x_{60} = -10.471975511966$$
$$x_{61} = 62.8318530717959$$
$$x_{62} = -73.3038285837618$$
$$x_{63} = -35.6047167406843$$
$$x_{64} = 50.2654824574367$$
$$x_{65} = -23.0383461263252$$
$$x_{66} = 94.2477796076938$$
$$x_{67} = -48.1710873550435$$
$$x_{68} = 46.0766922526503$$