Graph of the function intersects the axis X at f = 0
so we need to solve the equation:
$$- \sin^{2}{\left(x \right)} + \sin{\left(x \right)} = 0$$
Solve this equationThe points of intersection with the axis X:
Analytical solution$$x_{1} = 0$$
$$x_{2} = \frac{\pi}{2}$$
$$x_{3} = \pi$$
Numerical solution$$x_{1} = 32.9867223690379$$
$$x_{2} = -59.6902604182061$$
$$x_{3} = 64.4026493102586$$
$$x_{4} = 62.8318530717959$$
$$x_{5} = -87.9645943005142$$
$$x_{6} = 6.28318530717959$$
$$x_{7} = -54.9778709863297$$
$$x_{8} = 100.530964914873$$
$$x_{9} = 26.7035373768773$$
$$x_{10} = 70.6858345286456$$
$$x_{11} = -37.6991118430775$$
$$x_{12} = -34.5575191894877$$
$$x_{13} = 20.42035215177$$
$$x_{14} = 3.14159265358979$$
$$x_{15} = 78.5398163397448$$
$$x_{16} = 0$$
$$x_{17} = 76.969019673036$$
$$x_{18} = -31.4159265358979$$
$$x_{19} = 87.9645943005142$$
$$x_{20} = -17.2787597741434$$
$$x_{21} = -61.2610569243204$$
$$x_{22} = -73.8274272802392$$
$$x_{23} = -62.8318530717959$$
$$x_{24} = -65.9734457253857$$
$$x_{25} = -54.9778717129156$$
$$x_{26} = -53.4070751110265$$
$$x_{27} = -75.398223686155$$
$$x_{28} = -80.1106125810393$$
$$x_{29} = -72.2566310325652$$
$$x_{30} = 56.5486677646163$$
$$x_{31} = -42.4115006392452$$
$$x_{32} = 65.9734457253857$$
$$x_{33} = -28.2743338823081$$
$$x_{34} = 28.2743338823081$$
$$x_{35} = 15.707963267949$$
$$x_{36} = 83.2522050600807$$
$$x_{37} = -10.9955747331165$$
$$x_{38} = -15.707963267949$$
$$x_{39} = 1.57079651244662$$
$$x_{40} = 47.1238898038469$$
$$x_{41} = -48.6946861243056$$
$$x_{42} = 53.4070751110265$$
$$x_{43} = 12.5663706143592$$
$$x_{44} = 18.8495559215388$$
$$x_{45} = 69.1150383789755$$
$$x_{46} = -50.2654824574367$$
$$x_{47} = -10.9955739732138$$
$$x_{48} = -23.5619450064001$$
$$x_{49} = -21.9911485751286$$
$$x_{50} = 39.2699086388565$$
$$x_{51} = 37.6991118430775$$
$$x_{52} = 76.9690200976964$$
$$x_{53} = 7.85398173796495$$
$$x_{54} = 51.8362788966528$$
$$x_{55} = -36.1283154212439$$
$$x_{56} = 21.9911485751286$$
$$x_{57} = -4.7123888305818$$
$$x_{58} = 83.2522058001693$$
$$x_{59} = 43.9822971502571$$
$$x_{60} = -84.8230016469244$$
$$x_{61} = 14.1371670985871$$
$$x_{62} = 94.2477796076938$$
$$x_{63} = 34.5575191894877$$
$$x_{64} = -9.42477796076938$$
$$x_{65} = 95.8185760548644$$
$$x_{66} = -97.3893722612836$$
$$x_{67} = -25.1327412287183$$
$$x_{68} = -29.8451300972765$$
$$x_{69} = -1564.51314148772$$
$$x_{70} = 45.553093663481$$
$$x_{71} = 32.986723044911$$
$$x_{72} = -67.5442421642546$$
$$x_{73} = 97.3893722612836$$
$$x_{74} = -81.6814089933346$$
$$x_{75} = 58.1194647431527$$
$$x_{76} = -69.1150383789755$$
$$x_{77} = 89.5353908137952$$
$$x_{78} = 81.6814089933346$$
$$x_{79} = 25.1327412287183$$
$$x_{80} = -78.5398163397448$$
$$x_{81} = 120.951318648179$$
$$x_{82} = 9.42477796076938$$
$$x_{83} = -92.6769832292373$$
$$x_{84} = -6.28318530717959$$
$$x_{85} = -18.8495559215388$$
$$x_{86} = 91.106186954104$$
$$x_{87} = -4.71238903613963$$
$$x_{88} = 39.2699080280542$$
$$x_{89} = 59.6902604182061$$
$$x_{90} = -86.3937977915432$$
$$x_{91} = -94.2477796076938$$
$$x_{92} = -43.9822971502571$$
$$x_{93} = -40.8407044966673$$
$$x_{94} = 72.2566310325652$$
$$x_{95} = 50.2654824574367$$