Para hallar los extremos hay que resolver la ecuación
$$\frac{d}{d x} f{\left(x \right)} = 0$$
(la derivada es igual a cero),
y las raíces de esta ecuación serán los extremos de esta función:
$$\frac{d}{d x} f{\left(x \right)} = $$
primera derivada$$- \frac{2 \pi \sin{\left(\frac{\pi x}{3} + 1 \right)} \sin^{2}{\left(\frac{\pi}{4} + 1 \right)}}{3 \operatorname{atan}{\left(\frac{x}{3} \right)}} - \frac{2 \sin^{2}{\left(\frac{\pi}{4} + 1 \right)} \cos{\left(\frac{\pi x}{3} + 1 \right)}}{3 \left(\frac{x^{2}}{9} + 1\right) \operatorname{atan}^{2}{\left(\frac{x}{3} \right)}} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 65.0446471551009$$
$$x_{2} = -78.9546437734811$$
$$x_{3} = 101.04489663439$$
$$x_{4} = -30.9530107803312$$
$$x_{5} = -39.9537904111553$$
$$x_{6} = 59.0445554304911$$
$$x_{7} = 80.0447922733148$$
$$x_{8} = -12.9433916147356$$
$$x_{9} = 86.0448300650018$$
$$x_{10} = -33.9533415610825$$
$$x_{11} = -9.93505088725385$$
$$x_{12} = 62.0446046591783$$
$$x_{13} = 14.0353070912986$$
$$x_{14} = -45.9540729018243$$
$$x_{15} = -75.9546204775596$$
$$x_{16} = -90.9547148584446$$
$$x_{17} = 56.0444979691161$$
$$x_{18} = 53.0444303333317$$
$$x_{19} = 20.0403858521832$$
$$x_{20} = 8.01427314241055$$
$$x_{21} = 38.0438114021911$$
$$x_{22} = 92.0448606470826$$
$$x_{23} = -36.9535937642116$$
$$x_{24} = 4.9661486177045$$
$$x_{25} = -42.9539466795558$$
$$x_{26} = -84.9546831120399$$
$$x_{27} = 95.0448737941732$$
$$x_{28} = 47.0442534911438$$
$$x_{29} = -54.9543340044467$$
$$x_{30} = -21.9510457285375$$
$$x_{31} = -57.9543949106738$$
$$x_{32} = -96.9547408472594$$
$$x_{33} = -51.9542620784985$$
$$x_{34} = -81.9546645332808$$
$$x_{35} = 50.0443499739057$$
$$x_{36} = -69.9545644606477$$
$$x_{37} = 23.0415549303514$$
$$x_{38} = -66.9545305666873$$
$$x_{39} = 98.0448857428364$$
$$x_{40} = -48.9541763078526$$
$$x_{41} = -3.82803929263352$$
$$x_{42} = -24.9519448835217$$
$$x_{43} = 74.0447448152697$$
$$x_{44} = -87.9546998048222$$
$$x_{45} = 71.044716397544$$
$$x_{46} = 29.042884150723$$
$$x_{47} = 44.0441362706937$$
$$x_{48} = -72.9545942151565$$
$$x_{49} = 26.0423364267544$$
$$x_{50} = -27.9525651538481$$
$$x_{51} = 68.0446840916865$$
$$x_{52} = 35.0435815529748$$
$$x_{53} = -99.9547521079561$$
$$x_{54} = -60.9544469371416$$
$$x_{55} = 83.0448122029392$$
$$x_{56} = -93.9547284806413$$
$$x_{57} = 11.0290280072741$$
$$x_{58} = 41.0439919237837$$
$$x_{59} = 77.0447699444161$$
$$x_{60} = -15.9474278264858$$
$$x_{61} = 89.0448461358262$$
$$x_{62} = -63.954491728768$$
$$x_{63} = 1.59695520836124$$
$$x_{64} = -18.9496728516901$$
$$x_{65} = -6.91348234301887$$
$$x_{66} = 32.0432826687215$$
$$x_{67} = 17.0385256432214$$
Signos de extremos en los puntos:
2/pi \
(65.04464715510095, 1.31172758508052*sin |-- + 1|*cos(1 + 21.6815490517003*pi))
\4 /
2/pi \
(-78.95464377348107, -1.3047862642285*sin |-- + 1|*cos(1 - 26.3182145911604*pi))
\4 /
2/pi \
(101.04489663438974, 1.29776145539671*sin |-- + 1|*cos(1 + 33.6816322114632*pi))
\4 /
2/pi \
(-30.95301078033117, -1.35668918485075*sin |-- + 1|*cos(1 - 10.3176702601104*pi))
\4 /
2/pi \
(-39.95379041115532, -1.33703225834123*sin |-- + 1|*cos(1 - 13.3179301370518*pi))
\4 /
2/pi \
(59.044555430491144, 1.31576273106049*sin |-- + 1|*cos(1 + 19.6815184768304*pi))
\4 /
2/pi \
(80.0447922733148, 1.304346539933*sin |-- + 1|*cos(1 + 26.6815974244383*pi))
\4 /
2/pi \
(-12.943391614735598, -1.48915953919604*sin |-- + 1|*cos(1 - 4.31446387157853*pi))
\4 /
2/pi \
(86.04483006500179, 1.30213004566513*sin |-- + 1|*cos(1 + 28.6816100216673*pi))
\4 /
2/pi \
(-33.95334156108247, -1.34891906894198*sin |-- + 1|*cos(1 - 11.3177805203608*pi))
\4 /
2/pi \
(-9.93505088725385, -1.56550720658075*sin |-- + 1|*cos(1 - 3.31168362908462*pi))
\4 /
2/pi \
(62.04460465917826, 1.31364473687044*sin |-- + 1|*cos(1 + 20.6815348863928*pi))
\4 /
2/pi \
(14.03530709129865, 1.470352071004*sin |-- + 1|*cos(1 + 4.67843569709955*pi))
\4 /
2/pi \
(-45.95407290182433, -1.32836854643405*sin |-- + 1|*cos(1 - 15.3180243006081*pi))
\4 /
2/pi \
(-75.95462047755957, -1.30606310263924*sin |-- + 1|*cos(1 - 25.3182068258532*pi))
\4 /
2/pi \
(-90.95471485844465, -1.30053823873251*sin |-- + 1|*cos(1 - 30.3182382861482*pi))
\4 /
2/pi \
(56.044497969116144, 1.31811484408972*sin |-- + 1|*cos(1 + 18.6814993230387*pi))
\4 /
2/pi \
(53.04443033333174, 1.32074212613324*sin |-- + 1|*cos(1 + 17.6814767777772*pi))
\4 /
2/pi \
(20.040385852183245, 1.40626997160643*sin |-- + 1|*cos(1 + 6.68012861739441*pi))
\4 /
2/pi \
(8.01427314241055, 1.64933312677169*sin |-- + 1|*cos(1 + 2.67142438080352*pi))
\4 /
2/pi \
(38.04381140219114, 1.34039029216093*sin |-- + 1|*cos(1 + 12.681270467397*pi))
\4 /
2/pi \
(92.04486064708261, 1.30020830972951*sin |-- + 1|*cos(1 + 30.6816202156942*pi))
\4 /
2/pi \
(-36.95359376421159, -1.34247012048457*sin |-- + 1|*cos(1 - 12.3178645880705*pi))
\4 /
2/pi \
(4.9661486177045, 1.94670883527179*sin |-- + 1|*cos(1 + 1.65538287256817*pi))
\4 /
2/pi \
(-42.95394667955585, -1.33238528415755*sin |-- + 1|*cos(1 - 14.3179822265186*pi))
\4 /
2/pi \
(-84.95468311203993, -1.30250898080417*sin |-- + 1|*cos(1 - 28.3182277040133*pi))
\4 /
2/pi \
(95.04487379417324, 1.29934019869217*sin |-- + 1|*cos(1 + 31.6816245980577*pi))
\4 /
2/pi \
(47.04425349114377, 1.3270406709147*sin |-- + 1|*cos(1 + 15.6814178303813*pi))
\4 /
2/pi \
(-54.95433400444668, -1.3190352733355*sin |-- + 1|*cos(1 - 18.3181113348156*pi))
\4 /
2/pi \
(-21.9510457285375, -1.39375729818924*sin |-- + 1|*cos(1 - 7.31701524284583*pi))
\4 /
2/pi \
(-57.95439491067376, -1.31658839287297*sin |-- + 1|*cos(1 - 19.3181316368913*pi))
\4 /
2/pi \
(-96.95474084725943, -1.29881606368722*sin |-- + 1|*cos(1 - 32.3182469490865*pi))
\4 /
2/pi \
(-51.95426207849849, -1.32177460951675*sin |-- + 1|*cos(1 - 17.3180873594995*pi))
\4 /
2/pi \
(-81.95466453328078, -1.30360500382754*sin |-- + 1|*cos(1 - 27.3182215110936*pi))
\4 /
2/pi \
(50.04434997390568, 1.32369580955496*sin |-- + 1|*cos(1 + 16.6814499913019*pi))
\4 /
2/pi \
(-69.95456446064769, -1.30895397013167*sin |-- + 1|*cos(1 - 23.3181881535492*pi))
\4 /
2/pi \
(23.041554930351445, 1.38761199902279*sin |-- + 1|*cos(1 + 7.68051831011715*pi))
\4 /
2/pi \
(-66.95453056668727, -1.310599028721*sin |-- + 1|*cos(1 - 22.3181768555624*pi))
\4 /
2/pi \
(98.04488574283641, 1.29852621665345*sin |-- + 1|*cos(1 + 32.6816285809455*pi))
\4 /
2/pi \
(-48.95417630785262, -1.32486210408683*sin |-- + 1|*cos(1 - 16.3180587692842*pi))
\4 /
2/pi \
(-3.8280392926335174, -2.20731231649318*sin |-- + 1|*cos(1 - 1.27601309754451*pi))
\4 /
2/pi \
(-24.95194488352173, -1.37822717334108*sin |-- + 1|*cos(1 - 8.31731496117391*pi))
\4 /
2/pi \
(74.0447448152697, 1.30693120356289*sin |-- + 1|*cos(1 + 24.6815816050899*pi))
\4 /
2/pi \
(-87.95469980482221, -1.30148929378165*sin |-- + 1|*cos(1 - 29.3182332682741*pi))
\4 /
2/pi \
(71.04471639754401, 1.30839149060686*sin |-- + 1|*cos(1 + 23.6815721325147*pi))
\4 /
2/pi \
(29.042884150723005, 1.36252232855745*sin |-- + 1|*cos(1 + 9.68096138357433*pi))
\4 /
2/pi \
(44.04413627069369, 1.33085981755581*sin |-- + 1|*cos(1 + 14.6813787568979*pi))
\4 /
2/pi \
(-72.95459421515648, -1.30744760194208*sin |-- + 1|*cos(1 - 24.3181980717188*pi))
\4 /
2/pi \
(26.042336426754414, 1.37352747312723*sin |-- + 1|*cos(1 + 8.68077880891814*pi))
\4 /
2/pi \
(-27.952565153848056, -1.36623136279072*sin |-- + 1|*cos(1 - 9.31752171794935*pi))
\4 /
2/pi \
(68.04468409168655, 1.30998401694728*sin |-- + 1|*cos(1 + 22.6815613638955*pi))
\4 /
2/pi \
(35.04358155297482, 1.34644152121067*sin |-- + 1|*cos(1 + 11.6811938509916*pi))
\4 /
2/pi \
(-99.95475210795614, -1.2980339460358*sin |-- + 1|*cos(1 - 33.318250702652*pi))
\4 /
2/pi \
(-60.954446937141576, -1.31438953882109*sin |-- + 1|*cos(1 - 20.3181489790472*pi))
\4 /
2/pi \
(83.04481220293916, 1.3031973677048*sin |-- + 1|*cos(1 + 27.6816040676464*pi))
\4 /
2/pi \
(-93.95472848064131, -1.29964911426273*sin |-- + 1|*cos(1 - 31.3182428268804*pi))
\4 /
2/pi \
(11.029028007274148, 1.53231751888211*sin |-- + 1|*cos(1 + 3.67634266909138*pi))
\4 /
2/pi \
(41.04399192378365, 1.33526165554065*sin |-- + 1|*cos(1 + 13.6813306412612*pi))
\4 /
2/pi \
(77.04476994441606, 1.30558734849638*sin |-- + 1|*cos(1 + 25.681589981472*pi))
\4 /
2/pi \
(-15.947427826485766, -1.44419835099217*sin |-- + 1|*cos(1 - 5.31580927549525*pi))
\4 /
2/pi \
(89.04484613582618, 1.30113613277213*sin |-- + 1|*cos(1 + 29.6816153786087*pi))
\4 /
2/pi \
(-63.95449172876801, -1.31240284224882*sin |-- + 1|*cos(1 - 21.3181639095893*pi))
\4 /
2/pi \
(1.5969552083612446, 4.08858472866807*sin |-- + 1|*cos(1 + 0.532318402787082*pi))
\4 /
2/pi \
(-18.949672851690053, -1.41464191988161*sin |-- + 1|*cos(1 - 6.31655761723002*pi))
\4 /
2/pi \
(-6.913482343018871, -1.72208582895412*sin |-- + 1|*cos(1 - 2.30449411433962*pi))
\4 /
2/pi \
(32.04328266872153, 1.35368822220233*sin |-- + 1|*cos(1 + 10.6810942229072*pi))
\4 /
2/pi \
(17.038525643221387, 1.43214040501933*sin |-- + 1|*cos(1 + 5.67950854774046*pi))
\4 /
Intervalos de crecimiento y decrecimiento de la función:Hallemos los intervalos donde la función crece y decrece y también los puntos mínimos y máximos de la función, para lo cual miramos cómo se comporta la función en los extremos con desviación mínima del extremo:
Puntos mínimos de la función:
$$x_{1} = -78.9546437734811$$
$$x_{2} = -30.9530107803312$$
$$x_{3} = 80.0447922733148$$
$$x_{4} = -12.9433916147356$$
$$x_{5} = 86.0448300650018$$
$$x_{6} = 62.0446046591783$$
$$x_{7} = 14.0353070912986$$
$$x_{8} = -90.9547148584446$$
$$x_{9} = 56.0444979691161$$
$$x_{10} = 20.0403858521832$$
$$x_{11} = 8.01427314241055$$
$$x_{12} = 38.0438114021911$$
$$x_{13} = 92.0448606470826$$
$$x_{14} = -36.9535937642116$$
$$x_{15} = -42.9539466795558$$
$$x_{16} = -84.9546831120399$$
$$x_{17} = -54.9543340044467$$
$$x_{18} = -96.9547408472594$$
$$x_{19} = 50.0443499739057$$
$$x_{20} = -66.9545305666873$$
$$x_{21} = 98.0448857428364$$
$$x_{22} = -48.9541763078526$$
$$x_{23} = -24.9519448835217$$
$$x_{24} = 74.0447448152697$$
$$x_{25} = 44.0441362706937$$
$$x_{26} = -72.9545942151565$$
$$x_{27} = 26.0423364267544$$
$$x_{28} = 68.0446840916865$$
$$x_{29} = -60.9544469371416$$
$$x_{30} = 1.59695520836124$$
$$x_{31} = -18.9496728516901$$
$$x_{32} = -6.91348234301887$$
$$x_{33} = 32.0432826687215$$
Puntos máximos de la función:
$$x_{33} = 65.0446471551009$$
$$x_{33} = 101.04489663439$$
$$x_{33} = -39.9537904111553$$
$$x_{33} = 59.0445554304911$$
$$x_{33} = -33.9533415610825$$
$$x_{33} = -9.93505088725385$$
$$x_{33} = -45.9540729018243$$
$$x_{33} = -75.9546204775596$$
$$x_{33} = 53.0444303333317$$
$$x_{33} = 4.9661486177045$$
$$x_{33} = 95.0448737941732$$
$$x_{33} = 47.0442534911438$$
$$x_{33} = -21.9510457285375$$
$$x_{33} = -57.9543949106738$$
$$x_{33} = -51.9542620784985$$
$$x_{33} = -81.9546645332808$$
$$x_{33} = -69.9545644606477$$
$$x_{33} = 23.0415549303514$$
$$x_{33} = -3.82803929263352$$
$$x_{33} = -87.9546998048222$$
$$x_{33} = 71.044716397544$$
$$x_{33} = 29.042884150723$$
$$x_{33} = -27.9525651538481$$
$$x_{33} = 35.0435815529748$$
$$x_{33} = -99.9547521079561$$
$$x_{33} = 83.0448122029392$$
$$x_{33} = -93.9547284806413$$
$$x_{33} = 11.0290280072741$$
$$x_{33} = 41.0439919237837$$
$$x_{33} = 77.0447699444161$$
$$x_{33} = -15.9474278264858$$
$$x_{33} = 89.0448461358262$$
$$x_{33} = -63.954491728768$$
$$x_{33} = 17.0385256432214$$
Decrece en los intervalos
$$\left[98.0448857428364, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -96.9547408472594\right]$$