El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$3 \sin{\left(4 x + 1 \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{1}{4}$$
$$x_{2} = - \frac{1}{4} + \frac{\pi}{4}$$
Solución numérica$$x_{1} = 92.4269832808989$$
$$x_{2} = 9.96017612416683$$
$$x_{3} = -67.7942420521806$$
$$x_{4} = 52.371676947629$$
$$x_{5} = 100.280964914873$$
$$x_{6} = -31.6659265358979$$
$$x_{7} = 28.0243338823081$$
$$x_{8} = 61.7964549083984$$
$$x_{9} = -4.17699081698724$$
$$x_{10} = 6.03318530717959$$
$$x_{11} = 57.8694640914112$$
$$x_{12} = -34.0221210260903$$
$$x_{13} = -23.8119449019235$$
$$x_{14} = -15.957963267949$$
$$x_{15} = 25.6681393921158$$
$$x_{16} = -79.5752145031423$$
$$x_{17} = -27.7389357189107$$
$$x_{18} = 20.1703522483337$$
$$x_{19} = -78.0044181763474$$
$$x_{20} = 16.2433614313464$$
$$x_{21} = 83.0022053201295$$
$$x_{22} = -93.7123814442964$$
$$x_{23} = -48.1592879672443$$
$$x_{24} = 72.0066310325652$$
$$x_{25} = -81.9314089933346$$
$$x_{26} = 38.234510006475$$
$$x_{27} = -5.74778714378214$$
$$x_{28} = 12.3163706143592$$
$$x_{29} = -97.6393722612836$$
$$x_{30} = -57.5840659280137$$
$$x_{31} = -71.7212328691678$$
$$x_{32} = 31.9513246992954$$
$$x_{33} = -74.0774273593601$$
$$x_{34} = -89.7853906273091$$
$$x_{35} = -88.9999924639117$$
$$x_{36} = 34.3075191894877$$
$$x_{37} = 60.2256585816035$$
$$x_{38} = 39.8053063332699$$
$$x_{39} = -1.8207963267949$$
$$x_{40} = 56.2986677646163$$
$$x_{41} = 74.3628255227576$$
$$x_{42} = -92.1415851175014$$
$$x_{43} = 79.8606126665397$$
$$x_{44} = -59.9402604182061$$
$$x_{45} = -49.7300842940392$$
$$x_{46} = -70.1504365423729$$
$$x_{47} = 35.8783155162826$$
$$x_{48} = 82.2168071567321$$
$$x_{49} = -63.8672512351933$$
$$x_{50} = -23.026546738526$$
$$x_{51} = -26.1681393921158$$
$$x_{52} = -8.10398163397448$$
$$x_{53} = -75.648223686155$$
$$x_{54} = 351.608377202057$$
$$x_{55} = -53.6570751110265$$
$$x_{56} = 97.924770424681$$
$$x_{57} = 46.0884916404494$$
$$x_{58} = 70.4358347057703$$
$$x_{59} = 90.0707887907066$$
$$x_{60} = -45.803093477052$$
$$x_{61} = 8.38937979737193$$
$$x_{62} = -13.6017687777566$$
$$x_{63} = 48.4446861306418$$
$$x_{64} = -12.0309724509617$$
$$x_{65} = -37.9491118430775$$
$$x_{66} = -56.0132696012188$$
$$x_{67} = 30.3805283725005$$
$$x_{68} = -52.0862787842316$$
$$x_{69} = 64.1526493985908$$
$$x_{70} = -96.0685759344887$$
$$x_{71} = -41.8761026600648$$
$$x_{72} = 68.079640215578$$
$$x_{73} = -99.9955667514759$$
$$x_{74} = 496.907037430585$$
$$x_{75} = 78.2898163397448$$
$$x_{76} = 42.1615008234622$$
$$x_{77} = 96.3539740978861$$
$$x_{78} = -35.5929173528852$$
$$x_{79} = 86.1437979737193$$
$$x_{80} = 17.8141577581413$$
$$x_{81} = 24.0973430653209$$
$$x_{82} = 50.0154824574367$$
$$x_{83} = -9.67477796076938$$
$$x_{84} = -19.8849540849362$$
$$x_{85} = 53.9424732744239$$
$$x_{86} = 93.9977796076938$$
$$x_{87} = -30.095130209103$$
$$x_{88} = -85.8583998103219$$
$$x_{89} = 75.9336218495525$$
$$x_{90} = 5.24778714378214$$
$$x_{91} = 57.0840659280137$$
$$x_{92} = 2.10619449019234$$
$$x_{93} = 13.8871669411541$$
$$x_{94} = -8.88937979737193$$