El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\left|{\cos{\left(x \right)} + \frac{1}{2}}\right| = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = \frac{2 \pi}{3}$$
$$x_{2} = \frac{4 \pi}{3}$$
Solución numérica$$x_{1} = 20.943951023932$$
$$x_{2} = -83.7758040957278$$
$$x_{3} = -92.1533845053006$$
$$x_{4} = 79.5870138909414$$
$$x_{5} = 64.9262481741891$$
$$x_{6} = -79.5870138909414$$
$$x_{7} = -64.9262481741891$$
$$x_{8} = -54.4542726622231$$
$$x_{9} = -58.6430628670095$$
$$x_{10} = -29.3215314335047$$
$$x_{11} = 52.3598775598299$$
$$x_{12} = 92.1533845053006$$
$$x_{13} = 10.471975511966$$
$$x_{14} = 23.0383461263252$$
$$x_{15} = 4.18879020478639$$
$$x_{16} = 35.6047167406843$$
$$x_{17} = 29.3215314335047$$
$$x_{18} = 27.2271363311115$$
$$x_{19} = 14.6607657167524$$
$$x_{20} = -96.342174710087$$
$$x_{21} = -67.0206432765823$$
$$x_{22} = 98.4365698124802$$
$$x_{23} = 54.4542726622231$$
$$x_{24} = 67.0206432765823$$
$$x_{25} = -14.6607657167524$$
$$x_{26} = 85.870199198121$$
$$x_{27} = -23.0383461263252$$
$$x_{28} = -2.0943951023932$$
$$x_{29} = 58.6430628670095$$
$$x_{30} = -60.7374579694027$$
$$x_{31} = -16.7551608191456$$
$$x_{32} = -10.471975511966$$
$$x_{33} = -33.5103216382911$$
$$x_{34} = -48.1710873550435$$
$$x_{35} = -98.4365698124802$$
$$x_{36} = -73.3038285837618$$
$$x_{37} = -39.7935069454707$$
$$x_{38} = -4.18879020478639$$
$$x_{39} = 73.3038285837618$$
$$x_{40} = -121.474915938805$$
$$x_{41} = -46.0766922526503$$
$$x_{42} = -90.0589894029074$$
$$x_{43} = 8.37758040957278$$
$$x_{44} = 83.7758040957278$$
$$x_{45} = 96.342174710087$$
$$x_{46} = 48.1710873550435$$
$$x_{47} = -20.943951023932$$
$$x_{48} = 71.2094334813686$$
$$x_{49} = 2609.61629758192$$
$$x_{50} = -35.6047167406843$$
$$x_{51} = 41.8879020478639$$
$$x_{52} = -8.37758040957278$$
$$x_{53} = -71.2094334813686$$
$$x_{54} = -41.8879020478639$$
$$x_{55} = 39.7935069454707$$
$$x_{56} = -52.3598775598299$$
$$x_{57} = -77.4926187885482$$