El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\sin{\left(x + 1 \right)} \cos{\left(x - 1 \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = -1$$
$$x_{2} = 1 - \frac{\pi}{2}$$
$$x_{3} = 1 + \frac{\pi}{2}$$
Solución numérica$$x_{1} = -69.6858347057703$$
$$x_{2} = -38.2699081698724$$
$$x_{3} = 36.6991118430775$$
$$x_{4} = -47.6946861306418$$
$$x_{5} = -6.85398163397448$$
$$x_{6} = -211.057504117311$$
$$x_{7} = -161.221225333079$$
$$x_{8} = 58.6902604182061$$
$$x_{9} = -22.5619449019235$$
$$x_{10} = -13.5663706143592$$
$$x_{11} = 24.1327412287183$$
$$x_{12} = 77.9690200129499$$
$$x_{13} = 27.7035375555132$$
$$x_{14} = -73.2566310325652$$
$$x_{15} = -88.5353906273091$$
$$x_{16} = -28.845130209103$$
$$x_{17} = 64.9734457253857$$
$$x_{18} = 74.398223686155$$
$$x_{19} = -3.71238898038469$$
$$x_{20} = 2650.50419962979$$
$$x_{21} = 71.6858347057703$$
$$x_{22} = -22.9911485751286$$
$$x_{23} = -53.9778714378214$$
$$x_{24} = 93.6769832808989$$
$$x_{25} = -88.9645943005142$$
$$x_{26} = -72.8274273593601$$
$$x_{27} = -35.5575191894877$$
$$x_{28} = -79.5398163397448$$
$$x_{29} = 21.4203522483337$$
$$x_{30} = -9.99557428756428$$
$$x_{31} = 49.6946861306418$$
$$x_{32} = -116.809724509617$$
$$x_{33} = 80.6814089933346$$
$$x_{34} = -29.2743338823081$$
$$x_{35} = -75.9690200129499$$
$$x_{36} = -94.8185759344887$$
$$x_{37} = -25.7035375555132$$
$$x_{38} = -1$$
$$x_{39} = 20.9911485751286$$
$$x_{40} = 65.4026493985908$$
$$x_{41} = 11.9955742875643$$
$$x_{42} = 30.4159265358979$$
$$x_{43} = 93.2477796076938$$
$$x_{44} = 68.1150383789755$$
$$x_{45} = -57.5486677646163$$
$$x_{46} = -97.9601685880785$$
$$x_{47} = 8.42477796076938$$
$$x_{48} = -66.5442420521806$$
$$x_{49} = -82.2522053201295$$
$$x_{50} = -16.2787595947439$$
$$x_{51} = -44.9822971502571$$
$$x_{52} = 46.1238898038469$$
$$x_{53} = -63.8318530717959$$
$$x_{54} = 90.106186954104$$
$$x_{55} = -41.8407044966673$$
$$x_{56} = -7.28318530717959$$
$$x_{57} = 344.575191894877$$
$$x_{58} = -51.2654824574367$$
$$x_{59} = 15.1371669411541$$
$$x_{60} = 52.4070751110265$$
$$x_{61} = 2.14159265358979$$
$$x_{62} = 43.4115008234622$$
$$x_{63} = -95.2477796076938$$
$$x_{64} = -91.6769832808989$$
$$x_{65} = 62.261056745001$$
$$x_{66} = 87.3937979737193$$
$$x_{67} = -31.9867228626928$$
$$x_{68} = -85.8230016469244$$
$$x_{69} = 52.8362787842316$$
$$x_{70} = -60.261056745001$$
$$x_{71} = -44.553093477052$$
$$x_{72} = 5.71238898038469$$
$$x_{73} = 84.2522053201295$$
$$x_{74} = -66.9734457253857$$
$$x_{75} = -126.663706143592$$
$$x_{76} = 33.9867228626928$$
$$x_{77} = 86.9645943005142$$
$$x_{78} = 99.9601685880785$$
$$x_{79} = 40.2699081698724$$
$$x_{80} = 32282.0061082887$$
$$x_{81} = -16.707963267949$$
$$x_{82} = 18.2787595947439$$
$$x_{83} = 14.707963267949$$
$$x_{84} = 55.9778714378214$$
$$x_{85} = -50.8362787842316$$
$$x_{86} = -0.570796326794897$$
$$x_{87} = 96.3893722612836$$
$$x_{88} = 42.9822971502571$$
$$x_{89} = -19.8495559215388$$