El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$2 \cos{\left(\frac{x}{2} - \frac{\pi}{8} \right)} + 1 = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{13 \pi}{12}$$
$$x_{2} = \frac{19 \pi}{12}$$
Solución numérica$$x_{1} = 105.505153283057$$
$$x_{2} = -95.5567765466895$$
$$x_{3} = 42.6733002112614$$
$$x_{4} = 17.540558982543$$
$$x_{5} = -57.857664703612$$
$$x_{6} = 71.9948316447661$$
$$x_{7} = -82.9904059323304$$
$$x_{8} = -53.6688744988256$$
$$x_{9} = 80.3724120543389$$
$$x_{10} = 34.2957198016886$$
$$x_{11} = -78.801615727544$$
$$x_{12} = 30.1069295969022$$
$$x_{13} = -145.822259004126$$
$$x_{14} = -32.7249234748937$$
$$x_{15} = -66.2352451131848$$
$$x_{16} = -28.5361332701073$$
$$x_{17} = 55.2396708256205$$
$$x_{18} = -45.2912940892529$$
$$x_{19} = -70.4240353179712$$
$$x_{20} = -5633.1374272743$$
$$x_{21} = -15.9697626557481$$
$$x_{22} = 97.1275728734844$$
$$x_{23} = 21.7293491873294$$
$$x_{24} = -20.1585528605345$$
$$x_{25} = -723.875307264648$$
$$x_{26} = -91.3679863419031$$
$$x_{27} = -3.40339204138894$$
$$x_{28} = 84.5612022591253$$
$$x_{29} = -7.59218224617533$$
$$x_{30} = 92.9387826686981$$
$$x_{31} = 4.97418836818384$$
$$x_{32} = 9.16297857297023$$
$$x_{33} = 46.8620904160477$$
$$x_{34} = 59.4284610304069$$
$$x_{35} = 67.8060414399797$$
$$x_{36} = -799.273530950803$$
$$x_{37} = -41.1025038844665$$