El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\log{\left(- \sin{\left(x \right)} - \cos{\left(x \right)} \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{\pi}{2}$$
$$x_{2} = \pi$$
Solución numérica$$x_{1} = 86.3937979737193$$
$$x_{2} = 92.6769832808989$$
$$x_{3} = 3.14159265358979$$
$$x_{4} = -7.85398163397448$$
$$x_{5} = -64.4026493985908$$
$$x_{6} = -58.1194640914112$$
$$x_{7} = -20.4203522483337$$
$$x_{8} = 91.106186954104$$
$$x_{9} = -45.553093477052$$
$$x_{10} = 67.5442420521806$$
$$x_{11} = 84.8230016469244$$
$$x_{12} = -9.42477796076938$$
$$x_{13} = -59.6902604182061$$
$$x_{14} = 42.4115008234622$$
$$x_{15} = 78.5398163397448$$
$$x_{16} = -39.2699081698724$$
$$x_{17} = 17.2787595947439$$
$$x_{18} = -15.707963267949$$
$$x_{19} = -28.2743338823081$$
$$x_{20} = -21.9911485751286$$
$$x_{21} = -72.2566310325652$$
$$x_{22} = -84.8230016469244$$
$$x_{23} = -83.2522053201295$$
$$x_{24} = 23.5619449019235$$
$$x_{25} = -70.6858347057703$$
$$x_{26} = 61.261056745001$$
$$x_{27} = 97.3893722612836$$
$$x_{28} = 10.9955742875643$$
$$x_{29} = 47.1238898038469$$
$$x_{30} = -91.106186954104$$
$$x_{31} = -3.14159265358979$$
$$x_{32} = -14.1371669411541$$
$$x_{33} = 36.1283155162826$$
$$x_{34} = 29.845130209103$$
$$x_{35} = -97.3893722612836$$
$$x_{36} = 48.6946861306418$$
$$x_{37} = 80.1106126665397$$
$$x_{38} = 40.8407044966673$$
$$x_{39} = 21.9911485751286$$
$$x_{40} = -40.8407044966673$$
$$x_{41} = -47.1238898038469$$
$$x_{42} = 98.9601685880785$$
$$x_{43} = -32.9867228626928$$
$$x_{44} = 53.4070751110265$$
$$x_{45} = -95.8185759344887$$
$$x_{46} = 34.5575191894877$$
$$x_{47} = 72.2566310325652$$
$$x_{48} = -26.7035375555132$$
$$x_{49} = -103.672557568463$$
$$x_{50} = 9.42477796076938$$
$$x_{51} = 54.9778714378214$$
$$x_{52} = -1.5707963267949$$
$$x_{53} = 28.2743338823081$$
$$x_{54} = -65.9734457253857$$
$$x_{55} = 59.6902604182061$$
$$x_{56} = -51.8362787842316$$
$$x_{57} = 65.9734457253857$$
$$x_{58} = 4.71238898038469$$
$$x_{59} = -53.4070751110265$$
$$x_{60} = 73.8274273593601$$
$$x_{61} = -89.5353906273091$$
$$x_{62} = -76.9690200129499$$
$$x_{63} = 15.707963267949$$