El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\frac{\log{\left(\cos{\left(x \right)} \right)}}{x^{2}} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 2 \pi$$
Solución numérica$$x_{1} = 56.5486675910765$$
$$x_{2} = 75.3982238631513$$
$$x_{3} = 12.5663704222821$$
$$x_{4} = 37.6991114226912$$
$$x_{5} = -75.3982212667289$$
$$x_{6} = -31.4159267218315$$
$$x_{7} = -6.28318500859429$$
$$x_{8} = 6.28318425041486$$
$$x_{9} = -37.6991123409791$$
$$x_{10} = -12.5663702114039$$
$$x_{11} = -75.3982237850615$$
$$x_{12} = 56.5486697853444$$
$$x_{13} = 43.9822969520563$$
$$x_{14} = 43.9823007506628$$
$$x_{15} = -62.8318536636829$$
$$x_{16} = 81.6814067097954$$
$$x_{17} = -87.9645943582944$$
$$x_{18} = -50.2654848480677$$
$$x_{19} = 62.8318527292118$$
$$x_{20} = 37.6991140183594$$
$$x_{21} = 69.1150378100591$$
$$x_{22} = 31.4159236692146$$
$$x_{23} = -75.3982238842683$$
$$x_{24} = 81.6814092014976$$
$$x_{25} = 50.2654825592132$$
$$x_{26} = 6.28318536623994$$
$$x_{27} = 43.9822975717062$$
$$x_{28} = -6.28318509127283$$
$$x_{29} = 62.8318534194081$$
$$x_{30} = -12.5663711881532$$
$$x_{31} = -37.699115831174$$
$$x_{32} = -62.8318552794767$$
$$x_{33} = -6.28318703759797$$
$$x_{34} = 18.8495555495816$$
$$x_{35} = 87.9645944170753$$
$$x_{36} = 56.5486680400228$$
$$x_{37} = 100.530965170832$$
$$x_{38} = -18.8495552662988$$
$$x_{39} = -94.2477799274769$$
$$x_{40} = 31.4159268946166$$
$$x_{41} = -87.9645944082851$$
$$x_{42} = 25.1327406153308$$
$$x_{43} = 50.2654824463205$$
$$x_{44} = -50.2654822745065$$
$$x_{45} = 6.28318528379982$$
$$x_{46} = -43.9822971370899$$
$$x_{47} = 50.2654824267459$$
$$x_{48} = 75.3982240657869$$
$$x_{49} = 94.2477796642264$$
$$x_{50} = -31.4159240473036$$
$$x_{51} = 31.4159254853307$$
$$x_{52} = -81.6814088468767$$
$$x_{53} = 94.2477796093521$$
$$x_{54} = 69.1150385422669$$
$$x_{55} = 18.8495566653649$$
$$x_{56} = -25.1327415699717$$
$$x_{57} = 12.566371085894$$
$$x_{58} = -43.9822973028755$$
$$x_{59} = 37.6991120390888$$
$$x_{60} = 18.8495568924594$$
$$x_{61} = 100.530964751937$$
$$x_{62} = -31.4159262422395$$
$$x_{63} = -81.6814090383396$$
$$x_{64} = -18.8495564609393$$
$$x_{65} = -94.2477820859381$$
$$x_{66} = -25.1327401011047$$
$$x_{67} = -69.115038371213$$
$$x_{68} = 25.1327418019752$$
$$x_{69} = 62.8318541663282$$
$$x_{70} = -12.5663714894404$$
$$x_{71} = -87.9645943472471$$
$$x_{72} = 94.2477796240335$$
$$x_{73} = -56.5486674063126$$
$$x_{74} = -56.5486687958913$$
$$x_{75} = 75.3982227157249$$
$$x_{76} = -37.699111877239$$
$$x_{77} = 12.5663724671728$$
$$x_{78} = 87.9645943359894$$
$$x_{79} = 87.9645940945969$$
$$x_{80} = 81.6814088355208$$
$$x_{81} = -100.530965327794$$
$$x_{82} = 37.6991093650365$$
$$x_{83} = -81.681409137626$$
$$x_{84} = -100.530964572061$$
$$x_{85} = -37.6991117133998$$
$$x_{86} = -69.1150387430457$$
$$x_{87} = -56.5486680686757$$
$$x_{88} = 69.1150389965986$$
$$x_{89} = 43.9822971694655$$
$$x_{90} = -25.1327411327427$$
$$x_{91} = -69.1150373549062$$
$$x_{92} = -94.2477794361694$$
$$x_{93} = -50.2654827533158$$
$$x_{94} = -62.8318524778695$$
$$x_{95} = -43.9822971744421$$