El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$- 3 \sin{\left(2 x + 1 \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{1}{2}$$
$$x_{2} = - \frac{1}{2} + \frac{\pi}{2}$$
Solución numérica$$x_{1} = -46.053093477052$$
$$x_{2} = -47.6238898038469$$
$$x_{3} = -0.5$$
$$x_{4} = 54.4778714378214$$
$$x_{5} = -16.207963267949$$
$$x_{6} = 2.64159265358979$$
$$x_{7} = -8.35398163397448$$
$$x_{8} = 90.606186954104$$
$$x_{9} = 35.6283155162826$$
$$x_{10} = -69.6150383789755$$
$$x_{11} = 12.0663706143592$$
$$x_{12} = -66.4734457253857$$
$$x_{13} = -30.345130209103$$
$$x_{14} = 13.6371669411541$$
$$x_{15} = -44.4822971502571$$
$$x_{16} = 85.8937979737193$$
$$x_{17} = 82.7522053201295$$
$$x_{18} = -28.7743338823081$$
$$x_{19} = 57.6194640914112$$
$$x_{20} = -61.761056745001$$
$$x_{21} = 5.78318530717959$$
$$x_{22} = 19.9203522483337$$
$$x_{23} = 21.4911485751286$$
$$x_{24} = -90.0353906273091$$
$$x_{25} = 98.4601685880785$$
$$x_{26} = 10.4955742875643$$
$$x_{27} = 71.7566310325652$$
$$x_{28} = 4.21238898038469$$
$$x_{29} = -88.4645943005142$$
$$x_{30} = 60.761056745001$$
$$x_{31} = 40.3407044966673$$
$$x_{32} = 78.0398163397448$$
$$x_{33} = -41.3407044966673$$
$$x_{34} = 41.9115008234622$$
$$x_{35} = -9.92477796076938$$
$$x_{36} = -94.7477796076938$$
$$x_{37} = 106.314150222053$$
$$x_{38} = 93.7477796076938$$
$$x_{39} = -97.8893722612836$$
$$x_{40} = -83.7522053201295$$
$$x_{41} = 76.4690200129499$$
$$x_{42} = 24.6327412287183$$
$$x_{43} = -68.0442420521806$$
$$x_{44} = 63.9026493985908$$
$$x_{45} = -22.4911485751286$$
$$x_{46} = -60.1902604182061$$
$$x_{47} = -39.7699081698724$$
$$x_{48} = 32.4867228626928$$
$$x_{49} = -63.3318530717959$$
$$x_{50} = 18.3495559215388$$
$$x_{51} = 62.3318530717959$$
$$x_{52} = -154.4380400259$$
$$x_{53} = 38.7699081698724$$
$$x_{54} = 79.6106126665397$$
$$x_{55} = 84.3230016469244$$
$$x_{56} = -2.0707963267949$$
$$x_{57} = 56.0486677646163$$
$$x_{58} = -74.3274273593601$$
$$x_{59} = 68.6150383789755$$
$$x_{60} = 48.1946861306418$$
$$x_{61} = -53.9070751110265$$
$$x_{62} = -82.1814089933346$$
$$x_{63} = 100.030964914873$$
$$x_{64} = 26.2035375555132$$
$$x_{65} = -11.4955742875643$$
$$x_{66} = -25.6327412287183$$
$$x_{67} = -96.3185759344887$$
$$x_{68} = 269.676968208722$$
$$x_{69} = -77.4690200129499$$
$$x_{70} = -75.898223686155$$
$$x_{71} = -38.1991118430775$$
$$x_{72} = 43.4822971502571$$
$$x_{73} = 70.1858347057703$$
$$x_{74} = -19.3495559215388$$
$$x_{75} = 34.0575191894877$$
$$x_{76} = -33.4867228626928$$
$$x_{77} = -17.7787595947439$$
$$x_{78} = -91.606186954104$$
$$x_{79} = -31.9159265358979$$
$$x_{80} = -3.64159265358979$$
$$x_{81} = 46.6238898038469$$
$$x_{82} = -85.3230016469244$$
$$x_{83} = 92.1769832808989$$
$$x_{84} = 27.7743338823081$$
$$x_{85} = -52.3362787842316$$
$$x_{86} = -99.4601685880785$$
$$x_{87} = -24.0619449019235$$
$$x_{88} = -55.4778714378214$$
$$x_{89} = 49.7654824574367$$