El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\pi \cos{\left(\frac{x}{2} - \frac{\pi}{8} \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{3 \pi}{4}$$
$$x_{2} = \frac{5 \pi}{4}$$
Solución numérica$$x_{1} = -52.621676947629$$
$$x_{2} = -33.7721210260903$$
$$x_{3} = 60.4756585816035$$
$$x_{4} = -96.6039740978861$$
$$x_{5} = -115.453530019425$$
$$x_{6} = -71.4712328691678$$
$$x_{7} = 41.6261026600648$$
$$x_{8} = -8.63937979737193$$
$$x_{9} = -58.9048622548086$$
$$x_{10} = 3.92699081698724$$
$$x_{11} = 73.0420291959627$$
$$x_{12} = -14.9225651045515$$
$$x_{13} = -77.7544181763474$$
$$x_{14} = 22.776546738526$$
$$x_{15} = 79.3252145031423$$
$$x_{16} = 16.4933614313464$$
$$x_{17} = 10.2101761241668$$
$$x_{18} = 66.7588438887831$$
$$x_{19} = 85.6083998103219$$
$$x_{20} = -2.35619449019234$$
$$x_{21} = -21.2057504117311$$
$$x_{22} = 35.3429173528852$$
$$x_{23} = 98.174770424681$$
$$x_{24} = -90.3207887907066$$
$$x_{25} = -46.3384916404494$$
$$x_{26} = -27.4889357189107$$
$$x_{27} = -84.037603483527$$
$$x_{28} = -40.0553063332699$$
$$x_{29} = -65.1880475619882$$
$$x_{30} = -153.152641862502$$
$$x_{31} = 47.9092879672443$$
$$x_{32} = -102.887159405066$$
$$x_{33} = 54.1924732744239$$
$$x_{34} = 29.0597320457056$$
$$x_{35} = 91.8915851175014$$