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$$- \frac{2 x \cos{\left(x \sin{\left(x \right)} \right)}}{\left(x^{2} + 1\right)^{2}} - \frac{\left(x \cos{\left(x \right)} + \sin{\left(x \right)}\right) \sin{\left(x \sin{\left(x \right)} \right)}}{x^{2} + 1} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 7.97676636831914$$
$$x_{2} = -89.734243521408$$
$$x_{3} = 54.9960465503177$$
$$x_{4} = -47.8402712712771$$
$$x_{5} = 10.0937813002486$$
$$x_{6} = -71.7030063107861$$
$$x_{7} = 16.1081160019249$$
$$x_{8} = -67.7752088249099$$
$$x_{9} = 52.1023849728279$$
$$x_{10} = 38.1237450511423$$
$$x_{11} = -7.97676636831914$$
$$x_{12} = 6.2752885766894$$
$$x_{13} = -45.57502124367$$
$$x_{14} = -98.9702712571022$$
$$x_{15} = 98.7914235511575$$
$$x_{16} = -66.0210414605176$$
$$x_{17} = -35.8576547691741$$
$$x_{18} = -1.95292004499286$$
$$x_{19} = -29.1297138165908$$
$$x_{20} = 89.546556145968$$
$$x_{21} = 20.4690514480402$$
$$x_{22} = -17.7626740382366$$
$$x_{23} = -37.950046492929$$
$$x_{24} = -93.7595085442918$$
$$x_{25} = 32.7044195960411$$
$$x_{26} = -12.0143719793046$$
$$x_{27} = 84.1831191968517$$
$$x_{28} = 0$$
$$x_{29} = 48.4590986305698$$
$$x_{30} = -77.8900370009949$$
$$x_{31} = 73.1404148312981$$
$$x_{32} = 26.1324805306272$$
$$x_{33} = 40.4417636365925$$
$$x_{34} = -49.877921529335$$
$$x_{35} = -966.315101148601$$
$$x_{36} = 83.2642129723646$$
$$x_{37} = -51.8555535638033$$
$$x_{38} = -5.67939827599762$$
$$x_{39} = 14.2070920067649$$
$$x_{40} = -26.7408638885224$$
$$x_{41} = 42.1602546035537$$
$$x_{42} = 92.6877705165227$$
$$x_{43} = -80.1230908714195$$
$$x_{44} = -73.8409666663336$$
$$x_{45} = -9.75052796409632$$
$$x_{46} = -52.1023849728279$$
$$x_{47} = -42.4350488117844$$
$$x_{48} = -102.287282418745$$
$$x_{49} = 33.0169733091804$$
$$x_{50} = 18.0804083970234$$
$$x_{51} = -55.8069670767554$$
$$x_{52} = 30.2038613909654$$
$$x_{53} = 95.8290096729663$$
$$x_{54} = -45.8383541476887$$
$$x_{55} = 86.4053692620084$$
$$x_{56} = 73.8409666663336$$
$$x_{57} = -67.5590395974461$$
$$x_{58} = 58.1366581592079$$
$$x_{59} = 62.3033385218896$$
$$x_{60} = 1.95292004499286$$
$$x_{61} = 24.2415730617093$$
$$x_{62} = 80.1230908714195$$
$$x_{63} = 3.99288549953394$$
$$x_{64} = 45.8383541476887$$
$$x_{65} = 28.6099320629506$$
$$x_{66} = -13.7200913012033$$
$$x_{67} = 70.1330943577347$$
$$x_{68} = 67.5590395974461$$
$$x_{69} = -75.8254128646978$$
$$x_{70} = 64.4181679830524$$
$$x_{71} = 22.1333820182484$$
$$x_{72} = 91.7276583603743$$
$$x_{73} = -95.8290096729663$$
$$x_{74} = -39.5789723008709$$
$$x_{75} = 54.2591950662736$$
$$x_{76} = -3.99288549953394$$
$$x_{77} = -83.0690677531813$$
$$x_{78} = -57.9025814358805$$
$$x_{79} = 12.0143719793046$$
$$x_{80} = 94.2811049401377$$
$$x_{81} = -83.2642129723646$$
$$x_{82} = -100.145006299705$$
$$x_{83} = 36.1559452999376$$
$$x_{84} = -64.4181679830524$$
$$x_{85} = 44.1251537656813$$
$$x_{86} = -92.6877705165227$$
$$x_{87} = -33.0169733091804$$
$$x_{88} = -29.8785491134449$$
$$x_{89} = -81.0610306376236$$
$$x_{90} = -58.1366581592079$$
$$x_{91} = -19.7673188868061$$
$$x_{92} = 76.364510387349$$
$$x_{93} = -61.7879406679659$$
$$x_{94} = -42.1602546035537$$
Signos de extremos en los puntos:
(7.976766368319141, -0.000969999054658184)
(-89.73424352140799, 0.000124173599993961)
(54.996046550317736, 3.00495451871142e-6)
(-47.840271271277075, 0.000436739765563416)
(10.093781300248645, 0.00971707894867536)
(-71.70300631078614, 0.000194464692397773)
(16.108116001924948, 0.00383906640110577)
(-67.77520882490991, -0.000217652090001832)
(52.102384972827906, 0.000368233139290427)
(38.12374505114234, -0.000687558567184544)
(-7.976766368319141, -0.000969999054658184)
(6.275288576689398, 0.0247347968420277)
(-45.57502124366999, -5.27945161378254e-6)
(-98.97027125710224, 5.15719109738852e-7)
(98.79142355115755, -0.000102451124299323)
(-66.02104146051758, -0.00022936945735932)
(-35.85765476917407, -0.000777127968869317)
(-1.9529200449928572, -0.0496344373893902)
(-29.12971381659079, -0.0011771002803668)
(89.546556145968, -6.96259965388316e-7)
(20.469051448040197, -5.81673438663462e-5)
(-17.76267403823657, -0.00315906655066635)
(-37.95004649292897, -0.000693862617535356)
(-93.75950854429185, 0.000113741759109642)
(32.70441959604114, 0.000934056749695327)
(-12.014371979304647, 0.00687917737790704)
(84.18311919685172, 0.000141087542198971)
(0, 1)
(48.459098630569805, -0.000425659161668875)
(-77.89003700099485, -0.000164802791204193)
(73.14041483129806, 0.000186897680846366)
(26.132480530627223, -0.00146216903525372)
(40.44176363659251, -0.000611046106887358)
(-49.87792152933505, 0.000401798771272587)
(-966.3151011486011, 1.07093226156036e-6)
(83.26421297236459, -8.66033740421739e-7)
(-51.855553563803326, -3.58450588308517e-6)
(-5.679398275997625, -0.0299667249986111)
(14.207092006764867, -0.000173529855095618)
(-26.74086388852244, -2.61132063181247e-5)
(42.16025460355366, -0.000562270845438208)
(92.68777051652272, 6.27847603154114e-7)
(-80.12309087141952, 9.71923473309195e-7)
(-73.84096666633359, 1.24165667221037e-6)
(-9.750527964096317, -0.0104064273054665)
(-52.102384972827906, 0.000368233139290427)
(-42.43504881178441, 6.53980089884068e-6)
(-102.28728241874458, 9.55685403361958e-5)
(33.0169733091804, -1.38795633762528e-5)
(18.08040839702335, 0.00304957675366814)
(-55.80696707675536, 0.000320984132736766)
(30.20386139096544, -0.00109493692523046)
(95.82900967296632, -5.68111621580822e-7)
(-45.83835414768868, 0.000475699207157163)
(86.40536926200836, 7.74982779657211e-7)
(73.84096666633359, 1.24165667221037e-6)
(-67.55903959744609, 1.62116933232845e-6)
(58.136658159207926, -2.54387991560583e-6)
(62.30333852188964, 0.00025755228983126)
(1.9529200449928572, -0.0496344373893902)
(24.241573061709296, 0.00169876362802007)
(80.12309087141952, 9.71923473309195e-7)
(3.9928854995339367, -0.0584565031217252)
(45.83835414768868, 0.000475699207157163)
(28.609932062950648, -0.00122021026786115)
(-13.7200913012033, 0.00528294410782263)
(70.13309435773469, -0.000203266396136362)
(67.55903959744609, 1.62116933232845e-6)
(-75.82541286469778, 0.000173898113917656)
(64.41816798305243, -1.87001269895161e-6)
(22.133382018248373, -0.0020371133364322)
(91.7276583603743, -0.000118835926111172)
(-95.82900967296632, -5.68111621580822e-7)
(-39.57897230087091, 0.000637953929099493)
(54.259195066273605, -0.000339551454007951)
(-3.9928854995339367, -0.0584565031217252)
(-83.06906775318127, 0.000144896504838293)
(-57.9025814358805, 0.000298176352386008)
(12.014371979304647, 0.00687917737790704)
(94.2811049401377, -0.000112486863272038)
(-83.26421297236459, -8.66033740421739e-7)
(-100.14500629970492, 9.97006734438865e-5)
(36.15594529993759, 1.0570901483924e-5)
(-64.41816798305243, -1.87001269895161e-6)
(44.125153765681304, 0.000513339054773089)
(-92.68777051652272, 6.27847603154114e-7)
(-33.0169733091804, -1.38795633762528e-5)
(-29.878549113444887, 1.87251082857057e-5)
(-81.06103063762359, -0.000152163201774639)
(-58.136658159207926, -2.54387991560583e-6)
(-19.767318886806102, -0.00255258932294677)
(76.36451038734901, 0.000171451904492039)
(-61.78794066796588, -0.000261865670105154)
(-42.16025460355366, -0.000562270845438208)
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:
$$x_{1} = 7.97676636831914$$
$$x_{2} = -67.7752088249099$$
$$x_{3} = 38.1237450511423$$
$$x_{4} = -7.97676636831914$$
$$x_{5} = -45.57502124367$$
$$x_{6} = 98.7914235511575$$
$$x_{7} = -66.0210414605176$$
$$x_{8} = -35.8576547691741$$
$$x_{9} = -1.95292004499286$$
$$x_{10} = -29.1297138165908$$
$$x_{11} = 89.546556145968$$
$$x_{12} = 20.4690514480402$$
$$x_{13} = -17.7626740382366$$
$$x_{14} = -37.950046492929$$
$$x_{15} = 48.4590986305698$$
$$x_{16} = -77.8900370009949$$
$$x_{17} = 26.1324805306272$$
$$x_{18} = 40.4417636365925$$
$$x_{19} = 83.2642129723646$$
$$x_{20} = -51.8555535638033$$
$$x_{21} = -5.67939827599762$$
$$x_{22} = 14.2070920067649$$
$$x_{23} = -26.7408638885224$$
$$x_{24} = 42.1602546035537$$
$$x_{25} = -9.75052796409632$$
$$x_{26} = 33.0169733091804$$
$$x_{27} = 30.2038613909654$$
$$x_{28} = 95.8290096729663$$
$$x_{29} = 58.1366581592079$$
$$x_{30} = 1.95292004499286$$
$$x_{31} = 3.99288549953394$$
$$x_{32} = 28.6099320629506$$
$$x_{33} = 70.1330943577347$$
$$x_{34} = 64.4181679830524$$
$$x_{35} = 22.1333820182484$$
$$x_{36} = 91.7276583603743$$
$$x_{37} = -95.8290096729663$$
$$x_{38} = 54.2591950662736$$
$$x_{39} = -3.99288549953394$$
$$x_{40} = 94.2811049401377$$
$$x_{41} = -83.2642129723646$$
$$x_{42} = -64.4181679830524$$
$$x_{43} = -33.0169733091804$$
$$x_{44} = -81.0610306376236$$
$$x_{45} = -58.1366581592079$$
$$x_{46} = -19.7673188868061$$
$$x_{47} = -61.7879406679659$$
$$x_{48} = -42.1602546035537$$
Puntos máximos de la función:
$$x_{48} = -89.734243521408$$
$$x_{48} = 54.9960465503177$$
$$x_{48} = -47.8402712712771$$
$$x_{48} = 10.0937813002486$$
$$x_{48} = -71.7030063107861$$
$$x_{48} = 16.1081160019249$$
$$x_{48} = 52.1023849728279$$
$$x_{48} = 6.2752885766894$$
$$x_{48} = -98.9702712571022$$
$$x_{48} = -93.7595085442918$$
$$x_{48} = 32.7044195960411$$
$$x_{48} = -12.0143719793046$$
$$x_{48} = 84.1831191968517$$
$$x_{48} = 0$$
$$x_{48} = 73.1404148312981$$
$$x_{48} = -49.877921529335$$
$$x_{48} = -966.315101148601$$
$$x_{48} = 92.6877705165227$$
$$x_{48} = -80.1230908714195$$
$$x_{48} = -73.8409666663336$$
$$x_{48} = -52.1023849728279$$
$$x_{48} = -42.4350488117844$$
$$x_{48} = -102.287282418745$$
$$x_{48} = 18.0804083970234$$
$$x_{48} = -55.8069670767554$$
$$x_{48} = -45.8383541476887$$
$$x_{48} = 86.4053692620084$$
$$x_{48} = 73.8409666663336$$
$$x_{48} = -67.5590395974461$$
$$x_{48} = 62.3033385218896$$
$$x_{48} = 24.2415730617093$$
$$x_{48} = 80.1230908714195$$
$$x_{48} = 45.8383541476887$$
$$x_{48} = -13.7200913012033$$
$$x_{48} = 67.5590395974461$$
$$x_{48} = -75.8254128646978$$
$$x_{48} = -39.5789723008709$$
$$x_{48} = -83.0690677531813$$
$$x_{48} = -57.9025814358805$$
$$x_{48} = 12.0143719793046$$
$$x_{48} = -100.145006299705$$
$$x_{48} = 36.1559452999376$$
$$x_{48} = 44.1251537656813$$
$$x_{48} = -92.6877705165227$$
$$x_{48} = -29.8785491134449$$
$$x_{48} = 76.364510387349$$
Decrece en los intervalos
$$\left[98.7914235511575, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -95.8290096729663\right]$$