El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\frac{\tan{\left(\frac{x}{4} \right)}}{\tan^{2}{\left(\frac{x}{4} \right)} + 1} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 0$$
Solución numérica$$x_{1} = -43.9822971502571$$
$$x_{2} = -31.4159265358979$$
$$x_{3} = 6.28318530717959$$
$$x_{4} = -238.761041672824$$
$$x_{5} = 94.2477796076938$$
$$x_{6} = 50.2654824574367$$
$$x_{7} = 56.5486677646163$$
$$x_{8} = 43.9822971502571$$
$$x_{9} = -50.2654824574367$$
$$x_{10} = 37.6991118430775$$
$$x_{11} = -56.5486677646163$$
$$x_{12} = -62.8318530717959$$
$$x_{13} = -81.6814089933346$$
$$x_{14} = -6.28318530717959$$
$$x_{15} = -25.1327412287183$$
$$x_{16} = -75.398223686155$$
$$x_{17} = -106.814150222053$$
$$x_{18} = -69.1150383789755$$
$$x_{19} = 62.8318530717959$$
$$x_{20} = -18.8495559215388$$
$$x_{21} = 25.1327412287183$$
$$x_{22} = 100.530964914873$$
$$x_{23} = -87.9645943005142$$
$$x_{24} = 75.398223686155$$
$$x_{25} = 81.6814089933346$$
$$x_{26} = 87.9645943005142$$
$$x_{27} = 12.5663706143592$$
$$x_{28} = 69.1150383789755$$
$$x_{29} = 0$$
$$x_{30} = -37.6991118430775$$
$$x_{31} = 31.4159265358979$$
$$x_{32} = -12.5663706143592$$
$$x_{33} = -94.2477796076938$$
$$x_{34} = -100.530964914873$$
$$x_{35} = 18.8495559215388$$