El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\log{\left(\cos{\left(x \right)} + 2 \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = \pi$$
Solución numérica$$x_{1} = 84.8230013989283$$
$$x_{2} = 47.1238901095874$$
$$x_{3} = -34.5575189307135$$
$$x_{4} = 59.6902605990345$$
$$x_{5} = -91.1061866544445$$
$$x_{6} = 3.14159235388347$$
$$x_{7} = -53.4070748958642$$
$$x_{8} = -84.8230019484453$$
$$x_{9} = -40.8407041931413$$
$$x_{10} = 28.2743338652007$$
$$x_{11} = 135.088485232834$$
$$x_{12} = 9.42477767289303$$
$$x_{13} = -28.2743337157213$$
$$x_{14} = -9.42477775498414$$
$$x_{15} = 53.4070748204176$$
$$x_{16} = 91.1061866570418$$
$$x_{17} = 40.8407047891122$$
$$x_{18} = 78.5398165245928$$
$$x_{19} = -5626.59244272338$$
$$x_{20} = 65.9734449513383$$
$$x_{21} = 65.9734457528995$$
$$x_{22} = 21.9911487234764$$
$$x_{23} = -47.1238895063133$$
$$x_{24} = 21.9911478073732$$
$$x_{25} = -72.2566308734238$$
$$x_{26} = -40.8407047973861$$
$$x_{27} = -3.14159291033327$$
$$x_{28} = -59.6902604576442$$
$$x_{29} = 40.8407042442067$$
$$x_{30} = 9.4247782237219$$
$$x_{31} = 72.2566317986488$$
$$x_{32} = 21.9911485851966$$
$$x_{33} = 53.4070753779743$$
$$x_{34} = 47.1238895053604$$
$$x_{35} = -3.14159235845733$$
$$x_{36} = 1297.47776593514$$
$$x_{37} = 91.1061876920816$$
$$x_{38} = 84.8230019363831$$
$$x_{39} = -53.4070752848612$$
$$x_{40} = -65.9734457650159$$
$$x_{41} = -78.539816085332$$
$$x_{42} = 34.5575182863174$$
$$x_{43} = 97.3893719682512$$
$$x_{44} = -21.9911493226939$$
$$x_{45} = -59.6902596987591$$
$$x_{46} = -15.707963296528$$
$$x_{47} = -65.9734455035001$$
$$x_{48} = 78.5398161872027$$
$$x_{49} = 72.2566308798757$$
$$x_{50} = -15.7079633552461$$
$$x_{51} = 65.9734458402402$$
$$x_{52} = -21.9911485864513$$
$$x_{53} = 361.283156394675$$
$$x_{54} = -7216.23832551214$$
$$x_{55} = 28.2743337633749$$
$$x_{56} = -28.2743340569191$$
$$x_{57} = -72.2566311947681$$
$$x_{58} = 40.8407035528609$$
$$x_{59} = -91.1061872188649$$
$$x_{60} = 34.5575190296745$$
$$x_{61} = 15.7079630818076$$
$$x_{62} = -65.9734464426655$$
$$x_{63} = -15.7079625072695$$
$$x_{64} = 72.256631027719$$
$$x_{65} = 34.5575193851854$$
$$x_{66} = -34.5575194743092$$
$$x_{67} = 97.3893725320436$$
$$x_{68} = -97.3893724418701$$
$$x_{69} = -84.8230007465193$$
$$x_{70} = -72.2566317619041$$
$$x_{71} = -59.6902604759124$$
$$x_{72} = 15.7079634417622$$
$$x_{73} = -97.3893720374073$$
$$x_{74} = -47.1238900646908$$
$$x_{75} = -9.42477812767981$$
$$x_{76} = 3.14159295832046$$
$$x_{77} = -21.9911483911135$$
$$x_{78} = 91.1061872606575$$
$$x_{79} = 59.6902602213527$$
$$x_{80} = -304.734485852941$$
$$x_{81} = 28.2743346554806$$
$$x_{82} = -78.5398166211745$$
$$x_{83} = -84.8230013447959$$