El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\frac{\sin{\left(2 x \right)}}{2} + \cos{\left(x \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{\pi}{2}$$
$$x_{2} = \frac{\pi}{2}$$
Solución numérica$$x_{1} = -89.535441589746$$
$$x_{2} = -7.85396934854081$$
$$x_{3} = 76.9690200129499$$
$$x_{4} = 58.1194640914112$$
$$x_{5} = 14.1371669411541$$
$$x_{6} = -29.845130209103$$
$$x_{7} = 80.1106034946956$$
$$x_{8} = -36.1283155162826$$
$$x_{9} = -58.119532055033$$
$$x_{10} = -95.8185602777545$$
$$x_{11} = -4.71238898038469$$
$$x_{12} = 1.5707963267949$$
$$x_{13} = 73.827311651389$$
$$x_{14} = -83.2520989260588$$
$$x_{15} = 42.4114614973024$$
$$x_{16} = -67.5442420521806$$
$$x_{17} = -51.836262485438$$
$$x_{18} = -86.3937979737193$$
$$x_{19} = 86.3938908510206$$
$$x_{20} = 92.6768899714075$$
$$x_{21} = 4.71247207702943$$
$$x_{22} = 86.3937626449816$$
$$x_{23} = 48.6945895587878$$
$$x_{24} = 7.85398163397448$$
$$x_{25} = -7.8541073681749$$
$$x_{26} = 29.8451758719219$$
$$x_{27} = -61.261056745001$$
$$x_{28} = -73.8274273593601$$
$$x_{29} = 1393.29636850171$$
$$x_{30} = -45.5531406161696$$
$$x_{31} = -14.1372535946994$$
$$x_{32} = -95.8185821748531$$
$$x_{33} = 64.4026493985908$$
$$x_{34} = 89.5353906273091$$
$$x_{35} = -45.553042714615$$
$$x_{36} = -20.4202507419375$$
$$x_{37} = -39.2700111445703$$
$$x_{38} = 4.71228918668806$$
$$x_{39} = 42.4116084929189$$
$$x_{40} = 51.8362787842316$$
$$x_{41} = -48.6946861306418$$
$$x_{42} = -14.1371257126071$$
$$x_{43} = 70.6858347057703$$
$$x_{44} = -83.2523114345838$$
$$x_{45} = 26.7035375555132$$
$$x_{46} = 80.1107065596659$$
$$x_{47} = -64.4025511842224$$
$$x_{48} = -51.8362552464215$$
$$x_{49} = -23.5619449019235$$
$$x_{50} = -42.4115008234622$$
$$x_{51} = -45.5529627112364$$
$$x_{52} = 73.827477322712$$
$$x_{53} = 23.5620496503301$$
$$x_{54} = -1.57067615583836$$
$$x_{55} = -58.1194274499719$$
$$x_{56} = 32.9867228626928$$
$$x_{57} = 36.1283177986942$$
$$x_{58} = 67.5443499931316$$
$$x_{59} = 20.4203522483337$$
$$x_{60} = -1.5708395883501$$
$$x_{61} = -92.6769832808989$$
$$x_{62} = 29.8450277989543$$
$$x_{63} = 45.553093477052$$
$$x_{64} = -17.2787595947439$$
$$x_{65} = -80.1106126665397$$
$$x_{66} = 95.8185759344887$$