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$$\frac{2 x}{x^{2} + 1} - 2 \operatorname{acot}{\left(x \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 18717.3825921039$$
$$x_{2} = -41469.0097027937$$
$$x_{3} = -27908.3228655288$$
$$x_{4} = -21128.451639271$$
$$x_{5} = 39057.5547154358$$
$$x_{6} = 28887.0585662606$$
$$x_{7} = 42447.8004663952$$
$$x_{8} = 29734.5801929714$$
$$x_{9} = 41600.2364126928$$
$$x_{10} = 23802.0523520614$$
$$x_{11} = -28755.8386877142$$
$$x_{12} = -40621.447587593$$
$$x_{13} = -19433.5887869564$$
$$x_{14} = 10245.0412006996$$
$$x_{15} = 22107.1135839482$$
$$x_{16} = -29603.3595724168$$
$$x_{17} = 39905.113426091$$
$$x_{18} = -10960.8778764425$$
$$x_{19} = -14349.4901108771$$
$$x_{20} = 19564.7930550097$$
$$x_{21} = -32993.4859340089$$
$$x_{22} = 21259.6603274632$$
$$x_{23} = -25365.810848258$$
$$x_{24} = -30450.8850969459$$
$$x_{25} = 36514.8912641685$$
$$x_{26} = -11807.9338157736$$
$$x_{27} = -33841.0266214391$$
$$x_{28} = -16044.0821523617$$
$$x_{29} = 35667.3415095204$$
$$x_{30} = -31298.4148843908$$
$$x_{31} = -42316.5735052903$$
$$x_{32} = 17869.99050832$$
$$x_{33} = 17022.6195482377$$
$$x_{34} = -37231.2183043527$$
$$x_{35} = 33124.7089739066$$
$$x_{36} = -12655.0631680385$$
$$x_{37} = 31429.6368125843$$
$$x_{38} = 27192.0307619732$$
$$x_{39} = 26344.5255783821$$
$$x_{40} = -26213.3083727677$$
$$x_{41} = 12786.2285767811$$
$$x_{42} = 20412.2196081348$$
$$x_{43} = -32145.9485975863$$
$$x_{44} = -18586.1809993501$$
$$x_{45} = 28039.5419336107$$
$$x_{46} = 11939.0892257274$$
$$x_{47} = 22954.5779890773$$
$$x_{48} = 38209.9980244722$$
$$x_{49} = 16175.2730314267$$
$$x_{50} = 37362.4434906472$$
$$x_{51} = 33972.2501557217$$
$$x_{52} = -35536.1170902848$$
$$x_{53} = 13633.4257117535$$
$$x_{54} = -13502.2521178288$$
$$x_{55} = -16891.4245591221$$
$$x_{56} = -21975.9030580391$$
$$x_{57} = 30582.10639855$$
$$x_{58} = -36383.6664480288$$
$$x_{59} = 32277.1711035644$$
$$x_{60} = -23670.8387235676$$
$$x_{61} = -24518.3207010738$$
$$x_{62} = 40752.6740304247$$
$$x_{63} = -27060.8125814987$$
$$x_{64} = -17738.7919818582$$
$$x_{65} = 34819.7944072015$$
$$x_{66} = 25497.0269799384$$
$$x_{67} = 15327.9550113123$$
$$x_{68} = -38926.3288599295$$
$$x_{69} = -39773.8872675524$$
$$x_{70} = -22823.365825763$$
$$x_{71} = -34688.5704142599$$
$$x_{72} = -15196.7689456217$$
$$x_{73} = -38078.7724924216$$
$$x_{74} = 24649.5356458528$$
$$x_{75} = 11092.020896022$$
$$x_{76} = -20281.012992025$$
$$x_{77} = 14480.6704897809$$
Signos de extremos en los puntos:
(18717.38259210387, -1.99999999809709)
(-41469.00970279369, -1.99999999961233)
(-27908.322865528775, -1.99999999914406)
(-21128.451639271025, -1.99999999850661)
(39057.55471543576, -1.99999999956298)
(28887.058566260628, -1.99999999920108)
(42447.8004663952, -1.99999999963)
(29734.580192971367, -1.99999999924598)
(41600.23641269277, -1.99999999961477)
(23802.052352061375, -1.99999999882326)
(-28755.838687714244, -1.99999999919377)
(-40621.447587593044, -1.99999999959598)
(-19433.58878695641, -1.99999999823476)
(10245.041200699563, -1.99999999364843)
(22107.113583948245, -1.9999999986359)
(-29603.35957241684, -1.99999999923928)
(39905.113426091, -1.99999999958135)
(-10960.87787644252, -1.99999999445096)
(-14349.490110877094, -1.99999999676231)
(19564.79305500968, -1.99999999825836)
(-32993.48593400886, -1.99999999938758)
(21259.66032746322, -1.99999999852499)
(-25365.810848258036, -1.99999999896388)
(-30450.88509694595, -1.99999999928103)
(36514.89126416845, -1.9999999995)
(-11807.933815773578, -1.99999999521854)
(-33841.02662143908, -1.99999999941787)
(-16044.082152361707, -1.99999999741012)
(35667.3415095204, -1.99999999947596)
(-31298.41488439077, -1.99999999931944)
(-42316.573505290275, -1.9999999996277)
(17869.990508320032, -1.99999999791234)
(17022.619548237748, -1.99999999769932)
(-37231.21830435275, -1.99999999951906)
(33124.7089739066, -1.99999999939242)
(-12655.063168038458, -1.99999999583725)
(31429.636812584253, -1.99999999932511)
(27192.03076197315, -1.99999999909838)
(26344.525578382065, -1.99999999903943)
(-26213.308372767653, -1.99999999902979)
(12786.228576781117, -1.99999999592222)
(20412.219608134823, -1.99999999839997)
(-32145.948597586266, -1.99999999935486)
(-18586.180999350086, -1.99999999807013)
(28039.541933610733, -1.99999999915206)
(11939.089225727435, -1.99999999532301)
(22954.57798907731, -1.99999999873477)
(38209.99802447215, -1.99999999954338)
(16175.273031426721, -1.99999999745196)
(37362.44349064715, -1.99999999952243)
(33972.25015572168, -1.99999999942236)
(-35536.11709028476, -1.99999999947208)
(13633.425711753476, -1.99999999641327)
(-13502.25211782884, -1.99999999634324)
(-16891.424559122082, -1.99999999766344)
(-21975.903058039054, -1.99999999861957)
(30582.106398549957, -1.99999999928719)
(-36383.66644802879, -1.99999999949639)
(32277.171103564393, -1.99999999936009)
(-23670.838723567595, -1.99999999881018)
(-24518.320701073833, -1.99999999889101)
(40752.67403042468, -1.99999999959858)
(-27060.81258149867, -1.99999999908961)
(-17738.791981858223, -1.99999999788134)
(34819.79440720148, -1.99999999945013)
(25497.02697993837, -1.99999999897451)
(15327.955011312279, -1.99999999716247)
(-38926.32885992955, -1.99999999956003)
(-39773.887267552374, -1.99999999957858)
(-22823.365825763038, -1.99999999872018)
(-34688.570414259906, -1.99999999944597)
(-15196.768945621745, -1.99999999711327)
(-38078.77249242158, -1.99999999954023)
(24649.53564585282, -1.99999999890279)
(11092.020896021957, -1.9999999945814)
(-20281.012992024975, -1.9999999983792)
(14480.670489780925, -1.9999999968207)
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:
$$x_{1} = 18717.3825921039$$
$$x_{2} = 39057.5547154358$$
$$x_{3} = 10245.0412006996$$
$$x_{4} = 22107.1135839482$$
$$x_{5} = -16044.0821523617$$
$$x_{6} = -37231.2183043527$$
$$x_{7} = -32145.9485975863$$
$$x_{8} = 11939.0892257274$$
$$x_{9} = 38209.9980244722$$
$$x_{10} = 37362.4434906472$$
$$x_{11} = -16891.4245591221$$
$$x_{12} = 34819.7944072015$$
Puntos máximos de la función:
$$x_{12} = -40621.447587593$$
$$x_{12} = -14349.4901108771$$
$$x_{12} = -32993.4859340089$$
$$x_{12} = -42316.5735052903$$
$$x_{12} = 17022.6195482377$$
$$x_{12} = 31429.6368125843$$
$$x_{12} = -26213.3083727677$$
$$x_{12} = 32277.1711035644$$
$$x_{12} = 40752.6740304247$$
$$x_{12} = 25497.0269799384$$
$$x_{12} = -22823.365825763$$
$$x_{12} = -38078.7724924216$$
$$x_{12} = 24649.5356458528$$
$$x_{12} = 14480.6704897809$$
Decrece en los intervalos
$$\left[39057.5547154358, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -37231.2183043527\right]$$