El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$2 \sin{\left(\frac{x - \pi}{4} \right)} + 1 = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = \frac{\pi}{3}$$
$$x_{2} = \frac{17 \pi}{3}$$
Solución numérica$$x_{1} = 1.0471975511966$$
$$x_{2} = 805.294916870184$$
$$x_{3} = -57.5958653158129$$
$$x_{4} = -32.4631240870945$$
$$x_{5} = -99.4837673636768$$
$$x_{6} = 202.109127380943$$
$$x_{7} = 68.0678408277789$$
$$x_{8} = 42.9350995990605$$
$$x_{9} = 51.3126800086333$$
$$x_{10} = 118.333323285216$$
$$x_{11} = 17.8023583703422$$
$$x_{12} = -426.209403337015$$
$$x_{13} = -49.2182849062401$$
$$x_{14} = -7.33038285837618$$
$$x_{15} = 26.1799387799149$$
$$x_{16} = 93.2005820564972$$
$$x_{17} = -24.0855436775217$$
$$x_{18} = -74.3510261349584$$
$$x_{19} = -82.7286065445312$$
$$x_{20} = 76.4454212373516$$
$$x_{21} = 101.57816246607$$