El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$e^{3 x} \left(3 x + 2\right) = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{2}{3}$$
Solución numérica$$x_{1} = -88.8953333160534$$
$$x_{2} = -96.8929290565934$$
$$x_{3} = -19.0342904531655$$
$$x_{4} = -62.9077211086663$$
$$x_{5} = -11.2800841161841$$
$$x_{6} = -100.891877030423$$
$$x_{7} = -68.9039699996755$$
$$x_{8} = -26.9732609099696$$
$$x_{9} = -104.890909074067$$
$$x_{10} = -84.8967155451836$$
$$x_{11} = -13.1661828391732$$
$$x_{12} = -90.8946903653196$$
$$x_{13} = -21.0131835491248$$
$$x_{14} = -50.9181564771508$$
$$x_{15} = -70.9028710541052$$
$$x_{16} = -58.9106845280159$$
$$x_{17} = -44.9257214950719$$
$$x_{18} = -106.890453533698$$
$$x_{19} = -17.0627206598183$$
$$x_{20} = -60.9091499400071$$
$$x_{21} = -80.8982430984023$$
$$x_{22} = -72.9018366888535$$
$$x_{23} = -64.9063874568449$$
$$x_{24} = -82.8974597598681$$
$$x_{25} = -30.9569799798276$$
$$x_{26} = -102.891383186391$$
$$x_{27} = -40.9321666103254$$
$$x_{28} = -66.905139773456$$
$$x_{29} = -98.8923918645655$$
$$x_{30} = -42.9287742852393$$
$$x_{31} = -94.8934900958016$$
$$x_{32} = -28.96443695386$$
$$x_{33} = -38.9359586107227$$
$$x_{34} = -92.8940766068143$$
$$x_{35} = -74.9008613703326$$
$$x_{36} = -48.9204488749658$$
$$x_{37} = -46.9229596092229$$
$$x_{38} = -32.9505939998889$$
$$x_{39} = -24.9838689173196$$
$$x_{40} = -56.9123370791962$$
$$x_{41} = -36.940225566861$$
$$x_{42} = -34.945063001005$$
$$x_{43} = -52.9160550861198$$
$$x_{44} = -76.8999401799567$$
$$x_{45} = -22.9968687622801$$
$$x_{46} = -86.8960075934161$$
$$x_{47} = -0.666666666666667$$
$$x_{48} = -54.9141217561157$$
$$x_{49} = -78.8990687309661$$
$$x_{50} = -15.1032405495173$$