Hallemos los puntos de flexiones, para eso hay que resolver la ecuación
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0$$
(la segunda derivada es igual a cero),
las raíces de la ecuación obtenida serán los puntos de flexión para el gráfico de la función indicado:
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = $$
segunda derivada$$\frac{\sqrt[3]{\left(x + 2\right) \left(x^{2} + 4 x + 1\right)} \left(2 - \frac{2 \left(x^{2} + 4 x + 2 \left(x + 2\right)^{2} + 1\right)}{3 \left(x^{2} + 4 x + 1\right)} - \frac{x^{2} + 4 x + 2 \left(x + 2\right)^{2} + 1}{3 \left(x + 2\right)^{2}} + \frac{\left(x^{2} + 4 x + 2 \left(x + 2\right)^{2} + 1\right)^{2}}{9 \left(x + 2\right)^{2} \left(x^{2} + 4 x + 1\right)}\right)}{x^{2} + 4 x + 1} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 13595.3551706853$$
$$x_{2} = 20386.1309322134$$
$$x_{3} = 23779.3948913621$$
$$x_{4} = 35651.5566624874$$
$$x_{5} = -38067.860879902$$
$$x_{6} = 39890.7925658288$$
$$x_{7} = -11768.2859596051$$
$$x_{8} = 12745.7668706712$$
$$x_{9} = 30564.029185242$$
$$x_{10} = 34803.673999245$$
$$x_{11} = -32980.5841400403$$
$$x_{12} = 22931.1577402611$$
$$x_{13} = 25475.742961609$$
$$x_{14} = 43282.0100699056$$
$$x_{15} = -16864.3146630141$$
$$x_{16} = -32132.6538879474$$
$$x_{17} = 41586.4176289509$$
$$x_{18} = 27171.9489509878$$
$$x_{19} = 11895.8969218254$$
$$x_{20} = -33828.4980617993$$
$$x_{21} = 40738.6094295868$$
$$x_{22} = 33955.7774429341$$
$$x_{23} = 28868.0378701749$$
$$x_{24} = -31284.7059789048$$
$$x_{25} = 18689.1122074729$$
$$x_{26} = 29716.0446849717$$
$$x_{27} = 15293.8736344058$$
$$x_{28} = -17713.0729738729$$
$$x_{29} = -29588.751123943$$
$$x_{30} = -23652.0673021873$$
$$x_{31} = 28020.0067174112$$
$$x_{32} = 21234.5320460819$$
$$x_{33} = 32259.9382733895$$
$$x_{34} = 16142.8727452143$$
$$x_{35} = -35524.281588014$$
$$x_{36} = 33107.8659271269$$
$$x_{37} = -41459.1537020138$$
$$x_{38} = 22082.8720596826$$
$$x_{39} = 39042.966473615$$
$$x_{40} = 17840.4740633886$$
$$x_{41} = 38195.1305388373$$
$$x_{42} = -15166.4118955911$$
$$x_{43} = 31411.993176181$$
$$x_{44} = -36372.1532571523$$
$$x_{45} = -14317.2218374907$$
$$x_{46} = 16991.732969216$$
$$x_{47} = 36499.4264000808$$
$$x_{48} = -39763.5259557003$$
$$x_{49} = -25348.4275547676$$
$$x_{50} = -27044.6435149774$$
$$x_{51} = 37347.2840916655$$
$$x_{52} = -18561.7260417445$$
$$x_{53} = 24627.5885184677$$
$$x_{54} = 14444.7112563031$$
$$x_{55} = 26323.8620023876$$
$$x_{56} = -16015.4344345569$$
$$x_{57} = 42434.2176829333$$
$$x_{58} = 19537.6607784566$$
Intervalos de convexidad y concavidad:Hallemos los intervales donde la función es convexa o cóncava, para eso veamos cómo se comporta la función en los puntos de flexiones:
Cóncava en los intervalos
$$\left[32259.9382733895, \infty\right)$$
Convexa en los intervalos
$$\left(-\infty, -39763.5259557003\right]$$