El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\frac{\tan^{2}{\left(x \right)}}{\cos{\left(x \right)} + 1} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 0$$
Solución numérica$$x_{1} = -56.5486674686794$$
$$x_{2} = 62.8318526985726$$
$$x_{3} = -75.3982239232228$$
$$x_{4} = -100.530964275103$$
$$x_{5} = 37.6991120442398$$
$$x_{6} = 56.5486675695683$$
$$x_{7} = -18.8495544706379$$
$$x_{8} = 12.5663704058028$$
$$x_{9} = 12.5663701786553$$
$$x_{10} = -81.681409039085$$
$$x_{11} = 25.1327427789874$$
$$x_{12} = 94.2477796093518$$
$$x_{13} = -56.5486672305838$$
$$x_{14} = 100.530964732889$$
$$x_{15} = -62.8318517122106$$
$$x_{16} = -31.4159267584473$$
$$x_{17} = -50.2654822494279$$
$$x_{18} = -6.28318508460751$$
$$x_{19} = 75.3982243168224$$
$$x_{20} = 18.8495553963122$$
$$x_{21} = 43.9822981436805$$
$$x_{22} = 50.2654824463076$$
$$x_{23} = 43.9822971696108$$
$$x_{24} = 81.6814092465931$$
$$x_{25} = -18.849557335753$$
$$x_{26} = -75.3982227541863$$
$$x_{27} = -87.9645957501641$$
$$x_{28} = 87.9645943364787$$
$$x_{29} = 31.4159271324576$$
$$x_{30} = -25.1327417835141$$
$$x_{31} = -43.9822971743849$$
$$x_{32} = -12.5663700499606$$
$$x_{33} = -87.9645943580011$$
$$x_{34} = 6.28318528404309$$
$$x_{35} = 37.6991120807162$$
$$x_{36} = 0$$
$$x_{37} = 25.1327399026681$$
$$x_{38} = 125.663705199087$$
$$x_{39} = -37.6991118776952$$
$$x_{40} = -94.2477794137943$$
$$x_{41} = -31.4159271456979$$
$$x_{42} = -69.1150389650823$$
$$x_{43} = 62.8318525745282$$
$$x_{44} = -100.530964409549$$
$$x_{45} = 69.1150371341985$$
$$x_{46} = -62.83185458186$$