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$$\frac{1}{x^{3} \left(x^{2} + 1\right)} - \frac{3 \operatorname{atan}{\left(x \right)}}{x^{4}} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 7236.35716104477$$
$$x_{2} = 7672.48461667795$$
$$x_{3} = 1785.29502719907$$
$$x_{4} = -7856.7805079803$$
$$x_{5} = 5491.86794127918$$
$$x_{6} = 5709.9266730675$$
$$x_{7} = -10255.5037217841$$
$$x_{8} = -1533.60532068274$$
$$x_{9} = 9853.13914060572$$
$$x_{10} = -8074.84504579217$$
$$x_{11} = -7638.71629462345$$
$$x_{12} = -7202.58895891985$$
$$x_{13} = -5894.21857884875$$
$$x_{14} = 3965.49209127075$$
$$x_{15} = 2439.26010325451$$
$$x_{16} = -6112.27879598334$$
$$x_{17} = 8108.61346894407$$
$$x_{18} = 2875.29844141364$$
$$x_{19} = 3093.32834085196$$
$$x_{20} = 10943.4735346239$$
$$x_{21} = -3277.59942069308$$
$$x_{22} = 9635.07271631375$$
$$x_{23} = 4183.54063178357$$
$$x_{24} = 10289.2724725614$$
$$x_{25} = 3311.36352231564$$
$$x_{26} = -8510.97499518894$$
$$x_{27} = 10725.406383577$$
$$x_{28} = -5676.15912916437$$
$$x_{29} = 6146.04657865205$$
$$x_{30} = -9819.37043840689$$
$$x_{31} = -6766.46331179812$$
$$x_{32} = 4619.64383422034$$
$$x_{33} = -10909.7047215818$$
$$x_{34} = -9383.23782133527$$
$$x_{35} = -2187.49806367198$$
$$x_{36} = 10507.3393601875$$
$$x_{37} = -4367.82496072467$$
$$x_{38} = 8762.80891061845$$
$$x_{39} = -5240.04291424018$$
$$x_{40} = -2623.51387781694$$
$$x_{41} = 8544.74350435163$$
$$x_{42} = 3747.44606380726$$
$$x_{43} = -4149.77459307597$$
$$x_{44} = 1567.35153092681$$
$$x_{45} = 8980.87455080771$$
$$x_{46} = -1969.51063344567$$
$$x_{47} = 2003.26576637706$$
$$x_{48} = 5927.98624872058$$
$$x_{49} = -8292.90988250754$$
$$x_{50} = -10473.5705873586$$
$$x_{51} = 3529.40301266065$$
$$x_{52} = 4401.59131343521$$
$$x_{53} = -1751.54354846741$$
$$x_{54} = 2657.275113602$$
$$x_{55} = 5055.75344464919$$
$$x_{56} = 5273.81015770891$$
$$x_{57} = -2405.50036947356$$
$$x_{58} = 9417.00646804832$$
$$x_{59} = -2841.53603153169$$
$$x_{60} = -10691.6375900281$$
$$x_{61} = -4803.93108820379$$
$$x_{62} = 9198.94040830908$$
$$x_{63} = -6984.52590455775$$
$$x_{64} = 10071.2057295056$$
$$x_{65} = -6548.4012266516$$
$$x_{66} = -4585.87721090832$$
$$x_{67} = 6364.10758552026$$
$$x_{68} = -9165.17179234581$$
$$x_{69} = 7454.42069899149$$
$$x_{70} = 6582.16920220582$$
$$x_{71} = 2221.25583331424$$
$$x_{72} = -7420.65243427039$$
$$x_{73} = -10037.4370022285$$
$$x_{74} = 6800.23137017706$$
$$x_{75} = -3495.63829008982$$
$$x_{76} = -5021.98638138004$$
$$x_{77} = -8729.04036318698$$
$$x_{78} = -5458.10053864951$$
$$x_{79} = -3059.56499592463$$
$$x_{80} = -8947.1059678621$$
$$x_{81} = 7018.29403815943$$
$$x_{82} = 8326.67835035446$$
$$x_{83} = -3931.72641976461$$
$$x_{84} = -3713.68082542498$$
$$x_{85} = -9601.30404091578$$
$$x_{86} = 7890.54888267919$$
$$x_{87} = 4837.69794635806$$
$$x_{88} = -6330.33970145248$$
Signos de extremos en los puntos:
(7236.357161044765, 4.14497281294608e-12)
(7672.484616677953, 3.47756904322625e-12)
(1785.2950271990674, 2.7595292267938e-10)
(-7856.780507980298, 3.23855162026853e-12)
(5491.867941279178, 9.48220354976981e-12)
(5709.926673067501, 8.4368409146065e-12)
(-10255.503721784135, 1.45620301960021e-12)
(-1533.60532068274, 4.35310094708241e-10)
(9853.139140605721, 1.64198040059422e-12)
(-8074.845045792167, 2.98320463219618e-12)
(-7638.7162946234475, 3.52389159333441e-12)
(-7202.588958919849, 4.20354398603347e-12)
(-5894.218578848751, 7.6699804396491e-12)
(3965.4920912707485, 2.51859818262929e-11)
(2439.2601032545067, 1.08201225272451e-10)
(-6112.278795983339, 6.87804757216005e-12)
(8108.613468944074, 2.94608981868099e-12)
(2875.29844141364, 6.6065529857031e-11)
(3093.3283408519605, 5.30581895022233e-11)
(10943.47353462391, 1.19847515681457e-12)
(-3277.599420693085, 4.46033924641438e-11)
(9635.072716313749, 1.75600679027795e-12)
(4183.540631783572, 2.14497290356031e-11)
(10289.27247256137, 1.44191281411785e-12)
(3311.363522315636, 4.32529560149683e-11)
(-8510.974995188935, 2.54770680385954e-12)
(10725.406383577012, 1.27307159639954e-12)
(-5676.159129164371, 8.58830537874198e-12)
(6146.046578652049, 6.76530448711292e-12)
(-9819.370438406886, 1.65897861131416e-12)
(-6766.463311798117, 5.06983494489466e-12)
(4619.643834220337, 1.59306884116444e-11)
(-10909.704721581813, 1.2096383436691e-12)
(-9383.237821335268, 1.90121940910476e-12)
(-2187.4980636719824, 1.50020440270723e-10)
(10507.339360187512, 1.35398946704501e-12)
(-4367.82496072467, 1.88478100210337e-11)
(8762.808910618449, 2.33430876481498e-12)
(-5240.042914240175, 1.09159761878483e-11)
(-2623.5138778169407, 8.69689809102294e-11)
(8544.743504351633, 2.51762143305962e-12)
(3747.44606380726, 2.98428241496043e-11)
(-4149.774593075971, 2.19775726475667e-11)
(1567.351530926813, 4.07797166781175e-10)
(8980.874550807712, 2.16836905341858e-12)
(-1969.5106334456698, 2.05543848750264e-10)
(2003.2657663770606, 1.9532873246313e-10)
(5927.986248720577, 7.53965844131424e-12)
(-8292.909882507542, 2.7540111760754e-12)
(-10473.570587358558, 1.36712802563038e-12)
(3529.403012660651, 3.57221654370015e-11)
(4401.591313435207, 1.84173826289931e-11)
(-1751.5435484674142, 2.92212762453538e-10)
(2657.275113602, 8.36962996075909e-11)
(5055.753444649192, 1.21536724603538e-11)
(5273.810157708911, 1.070764518226e-11)
(-2405.500369473562, 1.12820661351227e-10)
(9417.00646804832, 1.88084025033226e-12)
(-2841.536031531689, 6.84483627174075e-11)
(-10691.637590028142, 1.28517221905977e-12)
(-4803.931088203787, 1.41668081825709e-11)
(9198.940408309081, 2.01779203752738e-12)
(-6984.525904557752, 4.60966636245985e-12)
(10071.205729505597, 1.5376164647985e-12)
(-6548.401226651605, 5.59334761106735e-12)
(-4585.8772109083175, 1.62851707682617e-11)
(6364.107585520264, 6.09345899183828e-12)
(-9165.17179234581, 2.04017715460926e-12)
(7454.420698991493, 3.79176216607348e-12)
(6582.16920220582, 5.50770592963753e-12)
(2221.255833314239, 1.43284642641616e-10)
(-7420.652434270391, 3.84376072549042e-12)
(-10037.437002228511, 1.55318731011956e-12)
(6800.231370177061, 4.99468552735776e-12)
(-3495.6382900898216, 3.6767263992254e-11)
(-5021.986381380039, 1.24004723284782e-11)
(-8729.040363186985, 2.36150406340518e-12)
(-5458.100538649511, 9.65927711161091e-12)
(-3059.5649959246252, 5.4834066067361e-11)
(-8947.105967862104, 2.19301312568368e-12)
(7018.2940381594335, 4.54345051878643e-12)
(8326.678350354463, 2.72064141906119e-12)
(-3931.726419764614, 2.58404265617627e-11)
(-3713.6808254249777, 3.06642040058813e-11)
(-9601.304040915778, 1.77459973482031e-12)
(7890.548882679185, 3.19715132297066e-12)
(4837.6979463580565, 1.38722362419844e-11)
(-6330.339701452477, 6.19148965399804e-12)
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:
La función no tiene puntos mínimos
La función no tiene puntos máximos
Decrece en todo el eje numérico