El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$3 \sin{\left(2 x + 4 \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = -2$$
$$x_{2} = -2 + \frac{\pi}{2}$$
Solución numérica$$x_{1} = 93.8185759344887$$
$$x_{2} = 24.7035375555132$$
$$x_{3} = -88.3937979737193$$
$$x_{4} = -0.429203673205103$$
$$x_{5} = -75.8274273593601$$
$$x_{6} = 4.28318530717959$$
$$x_{7} = -52.2654824574367$$
$$x_{8} = -74.2566310325652$$
$$x_{9} = 12.1371669411541$$
$$x_{10} = -38.1283155162826$$
$$x_{11} = 90.6769832808989$$
$$x_{12} = -97.8185759344887$$
$$x_{13} = -96.2477796076938$$
$$x_{14} = -83.6814089933346$$
$$x_{15} = -11.4247779607694$$
$$x_{16} = 71.8274273593601$$
$$x_{17} = -60.1194640914112$$
$$x_{18} = 40.4115008234622$$
$$x_{19} = 13.707963267949$$
$$x_{20} = 27.845130209103$$
$$x_{21} = 62.4026493985908$$
$$x_{22} = -25.5619449019235$$
$$x_{23} = 35.6991118430775$$
$$x_{24} = 588.619418874881$$
$$x_{25} = 84.3937979737193$$
$$x_{26} = -23.9911485751286$$
$$x_{27} = -3.5707963267949$$
$$x_{28} = 46.6946861306418$$
$$x_{29} = 111.097335529233$$
$$x_{30} = 5.85398163397448$$
$$x_{31} = 92.2477796076938$$
$$x_{32} = 2.71238898038469$$
$$x_{33} = -66.4026493985908$$
$$x_{34} = -69.5442420521806$$
$$x_{35} = -16.1371669411541$$
$$x_{36} = 63.9734457253857$$
$$x_{37} = 98.5309649148734$$
$$x_{38} = -61.6902604182061$$
$$x_{39} = 65.5442420521806$$
$$x_{40} = 48.2654824574367$$
$$x_{41} = -82.1106126665397$$
$$x_{42} = -50.6946861306418$$
$$x_{43} = -42.8407044966673$$
$$x_{44} = -33.4159265358979$$
$$x_{45} = -53.8362787842316$$
$$x_{46} = -39.6991118430775$$
$$x_{47} = 10.5663706143592$$
$$x_{48} = -30.2743338823081$$
$$x_{49} = 26.2743338823081$$
$$x_{50} = 32.5575191894877$$
$$x_{51} = 41.9822971502571$$
$$x_{52} = 34.1283155162826$$
$$x_{53} = -121.380520836412$$
$$x_{54} = -89.9645943005142$$
$$x_{55} = -63.261056745001$$
$$x_{56} = 56.1194640914112$$
$$x_{57} = -41.2699081698724$$
$$x_{58} = -19.2787595947439$$
$$x_{59} = 57.6902604182061$$
$$x_{60} = -9.85398163397448$$
$$x_{61} = 54.5486677646163$$
$$x_{62} = 49.8362787842316$$
$$x_{63} = 70.2566310325652$$
$$x_{64} = -45.9822971502571$$
$$x_{65} = 19.9911485751286$$
$$x_{66} = 87.5353906273091$$
$$x_{67} = -55.4070751110265$$
$$x_{68} = 78.1106126665397$$
$$x_{69} = 29.4159265358979$$
$$x_{70} = 43.553093477052$$
$$x_{71} = -22.4203522483337$$
$$x_{72} = -17.707963267949$$
$$x_{73} = 68.6858347057703$$
$$x_{74} = 18.4203522483337$$
$$x_{75} = -9789.631912259$$
$$x_{76} = -8.28318530717959$$
$$x_{77} = 76.5398163397448$$
$$x_{78} = 79.6814089933346$$
$$x_{79} = 21.5619449019235$$
$$x_{80} = -67.9734457253857$$
$$x_{81} = 100.101761241668$$
$$x_{82} = -91.5353906273091$$
$$x_{83} = -99.3893722612836$$
$$x_{84} = -77.398223686155$$
$$x_{85} = 85.9645943005142$$
$$x_{86} = -85.2522053201295$$
$$x_{87} = -31.845130209103$$
$$x_{88} = -44.4115008234622$$
$$x_{89} = -47.553093477052$$
$$x_{90} = -2$$