El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\frac{\cos{\left(x + 1 \right)}}{2} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = -1 + \frac{\pi}{2}$$
$$x_{2} = -1 + \frac{3 \pi}{2}$$
Solución numérica$$x_{1} = 16.2787595947439$$
$$x_{2} = 41.4115008234622$$
$$x_{3} = 94.8185759344887$$
$$x_{4} = -81.1106126665397$$
$$x_{5} = 25.7035375555132$$
$$x_{6} = 50.8362787842316$$
$$x_{7} = -30.845130209103$$
$$x_{8} = 47.6946861306418$$
$$x_{9} = 85.3937979737193$$
$$x_{10} = 44.553093477052$$
$$x_{11} = 97.9601685880785$$
$$x_{12} = -71.6858347057703$$
$$x_{13} = -15.1371669411541$$
$$x_{14} = 0.570796326794897$$
$$x_{15} = 28.845130209103$$
$$x_{16} = -1287.48219164502$$
$$x_{17} = 82.2522053201295$$
$$x_{18} = -65.4026493985908$$
$$x_{19} = -77.9690200129499$$
$$x_{20} = 31.9867228626928$$
$$x_{21} = -74.8274273593601$$
$$x_{22} = -96.8185759344887$$
$$x_{23} = -11.9955742875643$$
$$x_{24} = -8.85398163397448$$
$$x_{25} = -33.9867228626928$$
$$x_{26} = 6.85398163397448$$
$$x_{27} = -90.5353906273091$$
$$x_{28} = 38.2699081698724$$
$$x_{29} = 79.1106126665397$$
$$x_{30} = -2.5707963267949$$
$$x_{31} = 63.4026493985908$$
$$x_{32} = 75.9690200129499$$
$$x_{33} = -46.553093477052$$
$$x_{34} = -55.9778714378214$$
$$x_{35} = 72.8274273593601$$
$$x_{36} = -99.9601685880785$$
$$x_{37} = -40.2699081698724$$
$$x_{38} = -24.5619449019235$$
$$x_{39} = 53.9778714378214$$
$$x_{40} = -93.6769832808989$$
$$x_{41} = 3.71238898038469$$
$$x_{42} = 91.6769832808989$$
$$x_{43} = 101.101761241668$$
$$x_{44} = 69.6858347057703$$
$$x_{45} = -87.3937979737193$$
$$x_{46} = 13.1371669411541$$
$$x_{47} = 35.1283155162826$$
$$x_{48} = -62.261056745001$$
$$x_{49} = -18.2787595947439$$
$$x_{50} = 60.261056745001$$
$$x_{51} = -52.8362787842316$$
$$x_{52} = -5.71238898038469$$
$$x_{53} = -84.2522053201295$$
$$x_{54} = -68.5442420521806$$
$$x_{55} = 9.99557428756428$$
$$x_{56} = 57.1194640914112$$
$$x_{57} = 19.4203522483337$$
$$x_{58} = 547.207918051419$$
$$x_{59} = 88.5353906273091$$
$$x_{60} = 22.5619449019235$$
$$x_{61} = -21.4203522483337$$
$$x_{62} = -49.6946861306418$$
$$x_{63} = -43.4115008234622$$
$$x_{64} = -27.7035375555132$$
$$x_{65} = 66.5442420521806$$
$$x_{66} = -37.1283155162826$$
$$x_{67} = -59.1194640914112$$