El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\sin^{2}{\left(x \right)} + \sin{\left(x \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 0$$
$$x_{2} = - \frac{\pi}{2}$$
$$x_{3} = \pi$$
$$x_{4} = \frac{3 \pi}{2}$$
Solución numérica$$x_{1} = 31.4159265358979$$
$$x_{2} = 3.14159265358979$$
$$x_{3} = -34.5575191894877$$
$$x_{4} = -7.85398150061792$$
$$x_{5} = 91.106186954104$$
$$x_{6} = -51.8362785033387$$
$$x_{7} = -26.7035379972524$$
$$x_{8} = -62.8318530717959$$
$$x_{9} = -9.42477796076938$$
$$x_{10} = 42.4115007309741$$
$$x_{11} = -100.530964914873$$
$$x_{12} = -1.57079642735461$$
$$x_{13} = -89.5353907430632$$
$$x_{14} = 43.9822971502571$$
$$x_{15} = -31.4159265358979$$
$$x_{16} = 78.5398163397448$$
$$x_{17} = -70.6858346750384$$
$$x_{18} = 47.1238898038469$$
$$x_{19} = 23.5619450880496$$
$$x_{20} = -15.707963267949$$
$$x_{21} = -28.2743338823081$$
$$x_{22} = -21.9911485751286$$
$$x_{23} = 80.1106131505346$$
$$x_{24} = 56.5486677646163$$
$$x_{25} = -32.9867232359983$$
$$x_{26} = -20.4203520633206$$
$$x_{27} = -72.2566310325652$$
$$x_{28} = -84.8230016469244$$
$$x_{29} = 0$$
$$x_{30} = 40.8407044966673$$
$$x_{31} = -50.2654824574367$$
$$x_{32} = -91.106186954104$$
$$x_{33} = -64.4026492153213$$
$$x_{34} = -39.2699083493443$$
$$x_{35} = 25.1327412287183$$
$$x_{36} = 61.2610565484827$$
$$x_{37} = -94.2477796076938$$
$$x_{38} = -18.8495559215388$$
$$x_{39} = 12.5663706143592$$
$$x_{40} = 61.261057240759$$
$$x_{41} = -76.9690201700248$$
$$x_{42} = -3.14159265358979$$
$$x_{43} = -59.6902604182061$$
$$x_{44} = -58.1194640010631$$
$$x_{45} = 17.2787594994858$$
$$x_{46} = 4.71238880126794$$
$$x_{47} = 100.530964914873$$
$$x_{48} = -97.3893722612836$$
$$x_{49} = -76.969019611197$$
$$x_{50} = -47.1238898038469$$
$$x_{51} = 75.398223686155$$
$$x_{52} = -56.5486677646163$$
$$x_{53} = -26.7035375777291$$
$$x_{54} = 36.1283157927187$$
$$x_{55} = 86.3937978896245$$
$$x_{56} = 21.9911485751286$$
$$x_{57} = -40.8407044966673$$
$$x_{58} = -32.9867224730462$$
$$x_{59} = 73.8274274758159$$
$$x_{60} = 29.8451303173708$$
$$x_{61} = 98.9601686349023$$
$$x_{62} = -83.2522054990561$$
$$x_{63} = 98.9601685293103$$
$$x_{64} = 54.9778715673102$$
$$x_{65} = 34.5575191894877$$
$$x_{66} = -81.6814089933346$$
$$x_{67} = 50.2654824574367$$
$$x_{68} = -45.5530935853668$$
$$x_{69} = -87.9645943005142$$
$$x_{70} = 37.6991118430775$$
$$x_{71} = 54.9778709836$$
$$x_{72} = 28.2743338823081$$
$$x_{73} = -12.5663706143592$$
$$x_{74} = -65.9734457253857$$
$$x_{75} = 59.6902604182061$$
$$x_{76} = -95.8185758682081$$
$$x_{77} = 72.2566310325652$$
$$x_{78} = -6.28318530717959$$
$$x_{79} = 6.28318530717959$$
$$x_{80} = 94.2477796076938$$
$$x_{81} = -37.6991118430775$$
$$x_{82} = 65.9734457253857$$
$$x_{83} = -43.9822971502571$$
$$x_{84} = 10.9955738002317$$
$$x_{85} = 87.9645943005142$$
$$x_{86} = -14.1371668415708$$
$$x_{87} = -53.4070751110265$$
$$x_{88} = -89.5353901159531$$
$$x_{89} = 92.6769831047852$$
$$x_{90} = -51.8362786901812$$
$$x_{91} = 81.6814089933346$$
$$x_{92} = -75.398223686155$$
$$x_{93} = 17.2787599718548$$
$$x_{94} = 48.6946859526732$$
$$x_{95} = 67.5442422387326$$
$$x_{96} = 15.707963267949$$
$$x_{97} = 10.9955745314484$$
$$x_{98} = 84.8230016469244$$
$$x_{99} = 69.1150383789755$$