El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\sin{\left(x \right)} + \tan{\left(x \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 0$$
$$x_{2} = - \pi$$
$$x_{3} = \pi$$
$$x_{4} = 2 \pi$$
Solución numérica$$x_{1} = -100.530964914873$$
$$x_{2} = 15.7080436045967$$
$$x_{3} = 21.9911516421686$$
$$x_{4} = -25.1327412287183$$
$$x_{5} = 0$$
$$x_{6} = -75.398223686155$$
$$x_{7} = -50.2654824574367$$
$$x_{8} = -9.42485522090512$$
$$x_{9} = 81.6814089933346$$
$$x_{10} = 50.2654824574367$$
$$x_{11} = -43.9822971502571$$
$$x_{12} = -37.6991118430775$$
$$x_{13} = 25.1327412287183$$
$$x_{14} = -18.8495559215388$$
$$x_{15} = -72.2565592477495$$
$$x_{16} = -56.5486677646163$$
$$x_{17} = 18.8495559215388$$
$$x_{18} = -53.4071564235324$$
$$x_{19} = -6.28318530717959$$
$$x_{20} = 72.2566292956834$$
$$x_{21} = -62.8318530717959$$
$$x_{22} = 12.5663706143592$$
$$x_{23} = 84.82286496707$$
$$x_{24} = 56.5486677646163$$
$$x_{25} = -97.3894576417865$$
$$x_{26} = 69.1150383789755$$
$$x_{27} = 6.28318530717959$$
$$x_{28} = 37.6991118430775$$
$$x_{29} = -31.4159265358979$$
$$x_{30} = 100.530964914873$$
$$x_{31} = 59.6903450186765$$
$$x_{32} = -21.991151640849$$
$$x_{33} = 94.2477796076938$$
$$x_{34} = -28.2742578151769$$
$$x_{35} = -12.5663706143592$$
$$x_{36} = -94.2477796076938$$
$$x_{37} = -15.7079741660514$$
$$x_{38} = -59.6902757894932$$
$$x_{39} = 34.5574459696546$$
$$x_{40} = 28.2743275333221$$
$$x_{41} = 43.9822971502571$$
$$x_{42} = 75.398223686155$$
$$x_{43} = 62.8318530717959$$
$$x_{44} = 87.9645943005142$$
$$x_{45} = 65.9734548227005$$
$$x_{46} = -65.9734547149248$$
$$x_{47} = -81.6814089933346$$
$$x_{48} = -87.9645943005142$$
$$x_{49} = -69.1150383789755$$
$$x_{50} = 31.4159265358979$$
$$x_{51} = 78.5397471518186$$