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$$- \frac{\left(6 - \frac{6 x - \pi}{x}\right) \left(\left(6 - \frac{6 x - \pi}{x}\right) \sin{\left(\frac{x - \frac{\pi}{6}}{x} \right)} + 12 \cos{\left(\frac{x - \frac{\pi}{6}}{x} \right)}\right)}{36 x^{2}} = 0$$
Solve this equationThe roots of this equation
$$x_{1} = 41427.9403467868$$
$$x_{2} = 28714.7875583835$$
$$x_{3} = 30409.8315378329$$
$$x_{4} = -31471.0058012219$$
$$x_{5} = -16216.9552900844$$
$$x_{6} = 19392.5427495496$$
$$x_{7} = -34013.5990425367$$
$$x_{8} = 35495.0560134866$$
$$x_{9} = 22782.3209516532$$
$$x_{10} = 20239.9678730994$$
$$x_{11} = -15369.6802124353$$
$$x_{12} = -26385.9495771256$$
$$x_{13} = -28928.4520707411$$
$$x_{14} = 39732.8201872492$$
$$x_{15} = 16850.3714206536$$
$$x_{16} = -38251.320457622$$
$$x_{17} = -25538.4628497755$$
$$x_{18} = -14522.4454681802$$
$$x_{19} = -40793.9837085042$$
$$x_{20} = 8379.07545769266$$
$$x_{21} = 31257.3600790031$$
$$x_{22} = 36342.6041393053$$
$$x_{23} = 34647.5105812229$$
$$x_{24} = 38037.7077637257$$
$$x_{25} = 24477.2746595502$$
$$x_{26} = 32952.4286123356$$
$$x_{27} = 38885.2629463146$$
$$x_{28} = 23629.7933610518$$
$$x_{29} = 15155.7051220007$$
$$x_{30} = 25324.7639773204$$
$$x_{31} = 13461.1690245901$$
$$x_{32} = -23843.5151963346$$
$$x_{33} = -12828.1307845919$$
$$x_{34} = -7747.76587242727$$
$$x_{35} = 26172.2605544441$$
$$x_{36} = 12613.9653983573$$
$$x_{37} = -28080.9448420854$$
$$x_{38} = 14308.4180322449$$
$$x_{39} = -17911.6026252372$$
$$x_{40} = 33799.9680412469$$
$$x_{41} = -39946.4271408661$$
$$x_{42} = -22996.0562305385$$
$$x_{43} = -41641.5422488106$$
$$x_{44} = -36556.2233933028$$
$$x_{45} = -8594.02270901678$$
$$x_{46} = -34861.1373790492$$
$$x_{47} = 16003.0244805403$$
$$x_{48} = 21934.8584317107$$
$$x_{49} = -10287.2509837916$$
$$x_{50} = 27019.7637240838$$
$$x_{51} = -21301.1741305305$$
$$x_{52} = -9440.5408560508$$
$$x_{53} = 18545.1334355185$$
$$x_{54} = 32104.8925359025$$
$$x_{55} = 10072.734432923$$
$$x_{56} = -18758.9657663035$$
$$x_{57} = -32318.5329620286$$
$$x_{58} = -30623.4830038709$$
$$x_{59} = -27233.443806651$$
$$x_{60} = 27867.2728986532$$
$$x_{61} = -17064.2644377415$$
$$x_{62} = -19606.3505070677$$
$$x_{63} = -13675.2589566271$$
$$x_{64} = -42489.1026418116$$
$$x_{65} = -24690.9844192012$$
$$x_{66} = -35708.6789046493$$
$$x_{67} = 21087.4069575499$$
$$x_{68} = 11766.816446264$$
$$x_{69} = 40580.3793596321$$
$$x_{70} = -29775.964951333$$
$$x_{71} = 17697.7421211204$$
$$x_{72} = -11981.0740957299$$
$$x_{73} = 29562.3072418128$$
$$x_{74} = -11134.1063042828$$
$$x_{75} = -33166.0641447374$$
$$x_{76} = -37403.770639844$$
$$x_{77} = 42275.5030412496$$
$$x_{78} = 9225.83844291908$$
$$x_{79} = -39098.8726764577$$
$$x_{80} = -20453.7540689843$$
$$x_{81} = 10919.7341850356$$
$$x_{82} = -22148.6087369434$$
$$x_{83} = 37190.1547777458$$
You also need to calculate the limits of y '' for arguments seeking to indeterminate points of a function:
Points where there is an indetermination:
$$x_{1} = 0$$
True
True
- the limits are not equal, so
$$x_{1} = 0$$
- is an inflection point
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:
Have no bends at the whole real axis