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$$16 x \left(\cos{\left(x \right)} - 3\right) - 24 x - \left(4 x^{2} + 1\right) \sin{\left(x \right)} + 8 \sin{\left(x \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = -78.8206989968$$
$$x_{2} = 87.8038326385998$$
$$x_{3} = 30.9282248698152$$
$$x_{4} = -81.5079974024353$$
$$x_{5} = 103.885094336418$$
$$x_{6} = 94.0979324253178$$
$$x_{7} = -35.2045328488481$$
$$x_{8} = 23.0455822717581$$
$$x_{9} = 91.3481526048423$$
$$x_{10} = 24.4801588379355$$
$$x_{11} = 75.2099706756508$$
$$x_{12} = 35.2045328488481$$
$$x_{13} = -30.9282248698152$$
$$x_{14} = -72.5620960019177$$
$$x_{15} = -23.0455822717581$$
$$x_{16} = -60.0606261348886$$
$$x_{17} = -49.977927314077$$
$$x_{18} = 53.8215493164047$$
$$x_{19} = 43.6501870049194$$
$$x_{20} = 47.5945236040652$$
$$x_{21} = -85.0829736500492$$
$$x_{22} = 0$$
$$x_{23} = -91.3481526048423$$
$$x_{24} = 100.390633569853$$
$$x_{25} = 37.3050006534004$$
$$x_{26} = 85.0829736500492$$
$$x_{27} = -37.3050006534004$$
$$x_{28} = -53.8215493164047$$
$$x_{29} = -100.390633569853$$
$$x_{30} = -56.2948451774919$$
$$x_{31} = -97.6156688798395$$
$$x_{32} = -47.5945236040652$$
$$x_{33} = 97.6156688798395$$
$$x_{34} = 29.0732148790809$$
$$x_{35} = 78.8206989968$$
$$x_{36} = -66.3082300665959$$
$$x_{37} = 66.3082300665959$$
$$x_{38} = 49.977927314077$$
$$x_{39} = -29.0732148790809$$
$$x_{40} = -87.8038326385998$$
$$x_{41} = -41.3853706991217$$
$$x_{42} = -24.4801588379355$$
$$x_{43} = 68.9091183344345$$
$$x_{44} = 41.3853706991217$$
$$x_{45} = -43.6501870049194$$
$$x_{46} = -94.0979324253178$$
$$x_{47} = -68.9091183344345$$
$$x_{48} = -62.6045298836481$$
$$x_{49} = 56.2948451774919$$
$$x_{50} = 72.5620960019177$$
$$x_{51} = 81.5079974024353$$
$$x_{52} = 62.6045298836481$$
$$x_{53} = -75.2099706756508$$
$$x_{54} = 60.0606261348886$$
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
$$\left[103.885094336418, \infty\right)$$
Convexa en los intervalos
$$\left(-\infty, -97.6156688798395\right]$$