El gráfico de la función cruce el eje T con f = 0
o sea hay que resolver la ecuación:
$$\sin{\left(\frac{t}{2} + \frac{2}{5} \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje T:
Solución analítica$$t_{1} = - \frac{4}{5}$$
$$t_{2} = - \frac{4}{5} + 2 \pi$$
Solución numérica$$t_{1} = 24.3327412287183$$
$$t_{2} = 5.48318530717959$$
$$t_{3} = -19.6495559215388$$
$$t_{4} = -13.3663706143592$$
$$t_{5} = 80.8814089933346$$
$$t_{6} = 382.474303737955$$
$$t_{7} = -88.7645943005142$$
$$t_{8} = 11.7663706143592$$
$$t_{9} = 30.6159265358979$$
$$t_{10} = -44.7822971502571$$
$$t_{11} = 87.1645943005142$$
$$t_{12} = -51.0654824574367$$
$$t_{13} = -25.9327412287183$$
$$t_{14} = 93.4477796076938$$
$$t_{15} = 55.7486677646163$$
$$t_{16} = -95.0477796076938$$
$$t_{17} = 43.1822971502571$$
$$t_{18} = 62.0318530717959$$
$$t_{19} = -32.2159265358979$$
$$t_{20} = -82.4814089933346$$
$$t_{21} = -63.6318530717959$$
$$t_{22} = -101.330964914873$$
$$t_{23} = -57.3486677646163$$
$$t_{24} = 99.7309649148734$$
$$t_{25} = 68.3150383789754$$
$$t_{26} = -76.198223686155$$
$$t_{27} = -38.4991118430775$$
$$t_{28} = -69.9150383789755$$
$$t_{29} = 74.598223686155$$
$$t_{30} = 11478.5795562171$$
$$t_{31} = -7.08318530717959$$
$$t_{32} = 36.8991118430775$$
$$t_{33} = 156.27963267949$$
$$t_{34} = 49.4654824574367$$
$$t_{35} = -0.8$$
$$t_{36} = 18.0495559215388$$