Let's find the inflection points, we'll need to solve the equation for this
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0$$
(the second derivative equals zero),
the roots of this equation will be the inflection points for the specified function graph:
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = $$
the second derivative$$x \cos{\left(x \right)} + \sin{\left(x \right)} - 2 \cos{\left(x \right)} = 0$$
Solve this equationThe roots of this equation
$$x_{1} = 23.6081906531085$$
$$x_{2} = 89.5468125909757$$
$$x_{3} = 33.0189500585443$$
$$x_{4} = 98.9704806391999$$
$$x_{5} = 14.2188258742156$$
$$x_{6} = 0.853530113894593$$
$$x_{7} = 58.1372756833464$$
$$x_{8} = -64.4177044875113$$
$$x_{9} = 54.9967382846673$$
$$x_{10} = -20.4648368929299$$
$$x_{11} = -23.6009860496364$$
$$x_{12} = -4.85720028277455$$
$$x_{13} = 51.8563337271996$$
$$x_{14} = 17.3438402883766$$
$$x_{15} = 76.98235569319$$
$$x_{16} = -26.7383202665139$$
$$x_{17} = -36.1545187329187$$
$$x_{18} = 80.1234122276611$$
$$x_{19} = 39.2967137614233$$
$$x_{20} = -11.0719254025996$$
$$x_{21} = -98.9700721890598$$
$$x_{22} = -1.82641996054863$$
$$x_{23} = 64.4186688760215$$
$$x_{24} = -95.8287975174808$$
$$x_{25} = 45.5760378419384$$
$$x_{26} = -14.1988215852981$$
$$x_{27} = -29.8764910055328$$
$$x_{28} = -7.95410674917075$$
$$x_{29} = -58.1360915079299$$
$$x_{30} = -17.3304453861334$$
$$x_{31} = -67.5586174258189$$
$$x_{32} = -45.5741102182293$$
$$x_{33} = -39.2941199605515$$
$$x_{34} = 42.4362260836813$$
$$x_{35} = -86.4051090547584$$
$$x_{36} = 67.5594941902359$$
$$x_{37} = 11.1049660153822$$
$$x_{38} = 70.700389636084$$
$$x_{39} = 105.253038537472$$
$$x_{40} = -42.4340023126355$$
$$x_{41} = -80.1227889527036$$
$$x_{42} = -54.9954149087895$$
$$x_{43} = 26.7439295273141$$
$$x_{44} = 92.6880096500583$$
$$x_{45} = -76.9816805003412$$
$$x_{46} = -89.5463136256195$$
$$x_{47} = 2.60067613991532$$
$$x_{48} = 61.2779248313406$$
$$x_{49} = -70.6995890742758$$
$$x_{50} = -61.276858995262$$
$$x_{51} = 86.4056449682678$$
$$x_{52} = 20.4744283501428$$
$$x_{53} = 8.0186283585869$$
$$x_{54} = 73.8413460214977$$
$$x_{55} = -73.8406121428805$$
$$x_{56} = 83.2645101937716$$
$$x_{57} = -33.0152740675053$$
$$x_{58} = 29.8809815839878$$
$$x_{59} = -48.7144018403933$$
$$x_{60} = 48.7160887636725$$
$$x_{61} = 36.1575832324387$$
$$x_{62} = -92.6875439394849$$
$$x_{63} = 5.0310620206635$$
$$x_{64} = -51.8548450820895$$
$$x_{65} = -83.2639330708543$$
$$x_{66} = 95.8292331902999$$
Сonvexity and concavity intervals:Let’s find the intervals where the function is convex or concave, for this look at the behaviour of the function at the inflection points:
Concave at the intervals
$$\left[105.253038537472, \infty\right)$$
Convex at the intervals
$$\left(-\infty, -98.9700721890598\right]$$