El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$2 \cos{\left(x + 3 \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = -3 + \frac{\pi}{2}$$
$$x_{2} = -3 + \frac{3 \pi}{2}$$
Solución numérica$$x_{1} = 77.1106126665397$$
$$x_{2} = 39.4115008234622$$
$$x_{3} = -39.1283155162826$$
$$x_{4} = -48.553093477052$$
$$x_{5} = -1.4292036732051$$
$$x_{6} = 26.845130209103$$
$$x_{7} = 67.6858347057703$$
$$x_{8} = 1798.70338683375$$
$$x_{9} = 99.1017612416683$$
$$x_{10} = 61.4026493985908$$
$$x_{11} = -4.5707963267949$$
$$x_{12} = 64.5442420521806$$
$$x_{13} = -92.5353906273091$$
$$x_{14} = -20.2787595947439$$
$$x_{15} = -73.6858347057703$$
$$x_{16} = -42.2699081698724$$
$$x_{17} = 36.2699081698724$$
$$x_{18} = -64.261056745001$$
$$x_{19} = -86.2522053201295$$
$$x_{20} = -54.8362787842316$$
$$x_{21} = -51.6946861306418$$
$$x_{22} = -98.8185759344887$$
$$x_{23} = 95.9601685880785$$
$$x_{24} = 92.8185759344887$$
$$x_{25} = -79.9690200129499$$
$$x_{26} = -67.4026493985908$$
$$x_{27} = 23.7035375555132$$
$$x_{28} = -57.9778714378214$$
$$x_{29} = 89.6769832808989$$
$$x_{30} = -35.9867228626928$$
$$x_{31} = -1289.48219164502$$
$$x_{32} = 14.2787595947439$$
$$x_{33} = -13.9955742875643$$
$$x_{34} = 83.3937979737193$$
$$x_{35} = 20.5619449019235$$
$$x_{36} = 80.2522053201295$$
$$x_{37} = 11.1371669411541$$
$$x_{38} = -32.845130209103$$
$$x_{39} = -7.71238898038469$$
$$x_{40} = -23.4203522483337$$
$$x_{41} = 70.8274273593601$$
$$x_{42} = -26.5619449019235$$
$$x_{43} = -83.1106126665397$$
$$x_{44} = 58.261056745001$$
$$x_{45} = -45.4115008234622$$
$$x_{46} = -29.7035375555132$$
$$x_{47} = 42.553093477052$$
$$x_{48} = -76.8274273593601$$
$$x_{49} = 17.4203522483337$$
$$x_{50} = -17.1371669411541$$
$$x_{51} = -89.3937979737193$$
$$x_{52} = -10.8539816339745$$
$$x_{53} = 86.5353906273091$$
$$x_{54} = 29.9867228626928$$
$$x_{55} = -61.1194640914112$$
$$x_{56} = 48.8362787842316$$
$$x_{57} = 73.9690200129499$$
$$x_{58} = 55.1194640914112$$
$$x_{59} = 4.85398163397448$$
$$x_{60} = 45.6946861306418$$
$$x_{61} = -70.5442420521806$$
$$x_{62} = 33.1283155162826$$
$$x_{63} = 7.99557428756428$$
$$x_{64} = -95.6769832808989$$
$$x_{65} = 545.207918051419$$
$$x_{66} = 1.71238898038469$$
$$x_{67} = 51.9778714378214$$