Hallemos los puntos de flexiones, para eso hay que resolver la ecuación
$$\frac{d^{2}}{d z^{2}} f{\left(z \right)} = 0$$
(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:
$$\frac{d^{2}}{d z^{2}} f{\left(z \right)} = $$
segunda derivada$$z \left(z - 1\right) \cos{\left(z \right)} + 2 \left(2 z - 1\right) \sin{\left(z \right)} - 2 \cos{\left(z \right)} + 2 = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$z_{1} = -58.1881397678902$$
$$z_{2} = 36.2384122152916$$
$$z_{3} = -61.3251807497084$$
$$z_{4} = -5.2977838940059$$
$$z_{5} = 48.7765767115051$$
$$z_{6} = 67.603367225501$$
$$z_{7} = 17.5047523684329$$
$$z_{8} = 42.5054310008132$$
$$z_{9} = 80.1604865100088$$
$$z_{10} = 11.3391843094165$$
$$z_{11} = 99.0005585850349$$
$$z_{12} = -26.8518355730348$$
$$z_{13} = 0$$
$$z_{14} = 2.96262008759556$$
$$z_{15} = -45.6405967630826$$
$$z_{16} = -64.464649676656$$
$$z_{17} = -124.12487104562$$
$$z_{18} = 8.36902745888145$$
$$z_{19} = 33.1108983455767$$
$$z_{20} = -42.5032842836875$$
$$z_{21} = -86.4395238128539$$
$$z_{22} = 77.0216065575883$$
$$z_{23} = -92.719647476553$$
$$z_{24} = 55.050451439495$$
$$z_{25} = -77.0209250278353$$
$$z_{26} = -73.8808136084701$$
$$z_{27} = -80.159873004951$$
$$z_{28} = 86.4400520491554$$
$$z_{29} = -29.9738172371501$$
$$z_{30} = 95.8607275054178$$
$$z_{31} = -99.000155121353$$
$$z_{32} = 58.1893367986386$$
$$z_{33} = 70.7431490939608$$
$$z_{34} = 45.6425467136227$$
$$z_{35} = -48.7749387180784$$
$$z_{36} = -70.7423406341102$$
$$z_{37} = -33.107183821346$$
$$z_{38} = 23.7295001418395$$
$$z_{39} = 0.491376343682643$$
$$z_{40} = 51.9147419028124$$
$$z_{41} = -39.371290757943$$
$$z_{42} = -8.3151400497469$$
$$z_{43} = 39.373914357031$$
$$z_{44} = -17.4929232022982$$
$$z_{45} = -2.71289766542571$$
$$z_{46} = 64.465624059272$$
$$z_{47} = -89.5800250294686$$
$$z_{48} = -83.3002015310501$$
$$z_{49} = 83.300783808711$$
$$z_{50} = 14.4299183997612$$
$$z_{51} = -11.3132553947197$$
$$z_{52} = 26.8574851773111$$
$$z_{53} = 29.9780599454844$$
$$z_{54} = -36.2354787394051$$
$$z_{55} = 73.8815347948469$$
$$z_{56} = -23.7228444043321$$
$$z_{57} = 89.5805282402166$$
$$z_{58} = -67.6025073576017$$
$$z_{59} = -95.8602882969492$$
$$z_{60} = 61.326223421958$$
$$z_{61} = 5.37932133107065$$
$$z_{62} = -14.4105899058383$$
$$z_{63} = -55.04916098149$$
$$z_{64} = 20.6225155374891$$
$$z_{65} = 92.720107046927$$
$$z_{66} = -20.6129478764254$$
$$z_{67} = -51.9132364412918$$
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
$$\left[99.0005585850349, \infty\right)$$
Convexa en los intervalos
$$\left(-\infty, -95.8602882969492\right]$$