Hallemos los puntos de flexiones, para eso hay que resolver la ecuación
$$\frac{d^{2}}{d t^{2}} f{\left(t \right)} = 0$$
(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:
$$\frac{d^{2}}{d t^{2}} f{\left(t \right)} = $$
segunda derivada$$\frac{3 \left(t - \sin{\left(t \right)}\right)}{245} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$t_{1} = 0.000211459556825158$$
$$t_{2} = -0.000354780833531082$$
$$t_{3} = 9.87747756721168 \cdot 10^{-5}$$
$$t_{4} = 0.000338050263476576$$
$$t_{5} = -0.000344639079252657$$
$$t_{6} = -0.000507006152455581$$
$$t_{7} = 0.000487407608672123$$
$$t_{8} = -0.000398131957955096$$
$$t_{9} = -0.000275303790117805$$
$$t_{10} = -0.000181578586037745$$
$$t_{11} = -2.30650948881143 \cdot 10^{-5}$$
$$t_{12} = 0.000158265439061853$$
$$t_{13} = 0.000366607244447607$$
$$t_{14} = 0.000103586989846506$$
$$t_{15} = 0.00036154299149728$$
$$t_{16} = -0.000298238996058054$$
$$t_{17} = 0.000232068445398611$$
$$t_{18} = -0.000507615811698604$$
$$t_{19} = 0.000116491909675764$$
$$t_{20} = -0.000326636005021124$$
$$t_{21} = 0.000273636637121176$$
$$t_{22} = 0.000115526349792461$$
$$t_{23} = -0.000139957949205459$$
$$t_{24} = -0.000502595647167473$$
$$t_{25} = -0.000502428840121349$$
$$t_{26} = -0.000464475270529073$$
$$t_{27} = 0.000375705706494073$$
$$t_{28} = -0.000153828220060634$$
$$t_{29} = 0.000293332564268944$$
$$t_{30} = -8.65514725283832 \cdot 10^{-5}$$
$$t_{31} = 0.000196758597791821$$
$$t_{32} = 0.00029851614195885$$
$$t_{33} = 0.000262240651470109$$
$$t_{34} = 0.000186205615884384$$
$$t_{35} = 0.000249057296629685$$
$$t_{36} = 0.000502005684647592$$
$$t_{37} = -0.00032875274659132$$
$$t_{38} = -0.000119373030237671$$
$$t_{39} = -0.000509871240888593$$
$$t_{40} = -0.000294895013841546$$
$$t_{41} = 0.000506172775556784$$
$$t_{42} = -0.000229465112166451$$
$$t_{43} = -0.000150650416849474$$
$$t_{44} = -0.000203388307366495$$
$$t_{45} = -0.000101863601827664$$
$$t_{46} = -0.000208227179093703$$
$$t_{47} = -2.52124917530246 \cdot 10^{-5}$$
$$t_{48} = -1.80175000295583 \cdot 10^{-5}$$
$$t_{49} = -0.00032310291450612$$
$$t_{50} = 0$$
$$t_{51} = -0.000335842278172042$$
$$t_{52} = -0.000488510010521753$$
$$t_{53} = -0.000184329580774592$$
$$t_{54} = 0.000192883233096713$$
$$t_{55} = -0.000379691655066571$$
$$t_{56} = -1.47286646559006 \cdot 10^{-5}$$
$$t_{57} = -0.000358350854010069$$
$$t_{58} = -0.00024932579261574$$
$$t_{59} = 0.000277844031727139$$
$$t_{60} = 0.000506264531780356$$
$$t_{61} = -0.000436279556029867$$
$$t_{62} = 0.000345710440555261$$
$$t_{63} = 0.000147410258149109$$
$$t_{64} = -0.000402289544709377$$
$$t_{65} = -0.000272627253758062$$
$$t_{66} = -0.000157696828020104$$
$$t_{67} = 3.89118697646475 \cdot 10^{-6}$$
$$t_{68} = -0.000280100136547492$$
$$t_{69} = -9.83485862207226 \cdot 10^{-5}$$
$$t_{70} = 0.000418415496618132$$
$$t_{71} = -3.17741918727463 \cdot 10^{-5}$$
$$t_{72} = 0.000181808449257029$$
$$t_{73} = -0.000288977306130128$$
$$t_{74} = -0.00050591136865499$$
$$t_{75} = -1.98408831575722 \cdot 10^{-5}$$
$$t_{76} = -2.1240493551041 \cdot 10^{-5}$$
$$t_{77} = 0.000377213092012115$$
$$t_{78} = 0.000311466468124413$$
$$t_{79} = 0.000508795090664437$$
$$t_{80} = -0.000434263379753931$$
$$t_{81} = 0.000187685112066993$$
$$t_{82} = -0.000394851527639092$$
$$t_{83} = 0.000157056351702437$$
$$t_{84} = 0.000132920718924851$$
$$t_{85} = 0.000447176945911731$$
$$t_{86} = -0.000482789191711475$$
$$t_{87} = 2.49127326983744 \cdot 10^{-5}$$
$$t_{88} = -1.46863857903661 \cdot 10^{-6}$$
$$t_{89} = -8.95231865768492 \cdot 10^{-5}$$
$$t_{90} = 0.000466732788188678$$
$$t_{91} = -0.000512635363151742$$
$$t_{92} = -0.000486773542081202$$
$$t_{93} = 0.000505642059113322$$
$$t_{94} = 0.000137906691427903$$
$$t_{95} = -0.0005044477914485$$
$$t_{96} = -0.000175577662192217$$
$$t_{97} = -0.000135184808718669$$
$$t_{98} = -0.000165445288810936$$
$$t_{99} = -0.000152751605225569$$
$$t_{100} = 0.000356917401227436$$
$$t_{101} = 0.000207796431907736$$
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
$$\left[0.000506264531780356, \infty\right)$$
Convexa en los intervalos
$$\left(-\infty, -0.000512635363151742\right]$$