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$$\frac{2 \cos{\left(2 x \right)}}{x - 1} - \frac{\sin{\left(2 x \right)}}{\left(x - 1\right)^{2}} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 18.0494987719381$$
$$x_{2} = -10.1878453044909$$
$$x_{3} = -47.9041761074919$$
$$x_{4} = 52.6168337179501$$
$$x_{5} = -41.6202371710741$$
$$x_{6} = -85.6055131901373$$
$$x_{7} = 55.7587042438767$$
$$x_{8} = 74.6094292709781$$
$$x_{9} = -2.28057021563236$$
$$x_{10} = -76.1803827297937$$
$$x_{11} = 54.1877730844831$$
$$x_{12} = 11.7577501031099$$
$$x_{13} = -5.45915944962428$$
$$x_{14} = -84.0346635398793$$
$$x_{15} = -0.637196330969125$$
$$x_{16} = -11.7613921271159$$
$$x_{17} = -62.0424894121024$$
$$x_{18} = -38.478177732588$$
$$x_{19} = 96.601359096144$$
$$x_{20} = 10.1829786980484$$
$$x_{21} = 63.6132585554971$$
$$x_{22} = 25.9081038458568$$
$$x_{23} = -33.7649303669424$$
$$x_{24} = 40.0489044548563$$
$$x_{25} = -40.049216384194$$
$$x_{26} = -49.4751315219363$$
$$x_{27} = 93.4596775892801$$
$$x_{28} = 69.8968079909424$$
$$x_{29} = 68.3259270041136$$
$$x_{30} = -54.1879434234347$$
$$x_{31} = -57.3297800576259$$
$$x_{32} = -46.3332101330021$$
$$x_{33} = 84.0345927265613$$
$$x_{34} = 91.8888345323567$$
$$x_{35} = 22.7650624601772$$
$$x_{36} = 82.4637383451864$$
$$x_{37} = 85.6054449521595$$
$$x_{38} = 90.317989831739$$
$$x_{39} = 60.471454983256$$
$$x_{40} = -77.7512436659628$$
$$x_{41} = 88.7471433991491$$
$$x_{42} = 8.60656064608673$$
$$x_{43} = -24.3374775388136$$
$$x_{44} = 46.33297711484$$
$$x_{45} = -18.0510381254578$$
$$x_{46} = 38.4778397936073$$
$$x_{47} = -93.4597348386756$$
$$x_{48} = -140.584505525547$$
$$x_{49} = 99.7430349489701$$
$$x_{50} = -90.3180511337085$$
$$x_{51} = 2.15134433588925$$
$$x_{52} = -99.743085211956$$
$$x_{53} = 3.83985112537054$$
$$x_{54} = 41.6199483594113$$
$$x_{55} = -3.87589679173726$$
$$x_{56} = -98.1722495795572$$
$$x_{57} = -25.9088498373569$$
$$x_{58} = -69.8969103540797$$
$$x_{59} = 24.3366319328506$$
$$x_{60} = 32.1933108467876$$
$$x_{61} = -27.4801585795776$$
$$x_{62} = -65.1842703012744$$
$$x_{63} = 30.6220895261697$$
$$x_{64} = -60.4715917520353$$
$$x_{65} = 66.7550419722411$$
$$x_{66} = -68.3260341292281$$
$$x_{67} = -35.336037565231$$
$$x_{68} = -32.1937937404494$$
$$x_{69} = 16.4772142695041$$
$$x_{70} = -91.8888937560759$$
$$x_{71} = 62.042359483332$$
$$x_{72} = 76.1802965592094$$
$$x_{73} = -16.4790625040945$$
$$x_{74} = -82.4638118824473$$
$$x_{75} = -55.7588651168628$$
$$x_{76} = 19.6215319912886$$
$$x_{77} = 47.9039581285518$$
$$x_{78} = 33.76449140679$$
$$x_{79} = -71.4677831150521$$
$$x_{80} = 44.7619828411789$$
$$x_{81} = -79.3221020750003$$
$$x_{82} = -13.3343352045635$$
$$x_{83} = 71.4676852032561$$
$$x_{84} = 77.7511609427056$$
$$x_{85} = 98.172197695036$$
$$x_{86} = -19.6228339741551$$
$$x_{87} = -63.6133821448946$$
Signos de extremos en los puntos:
(18.049498771938094, -0.0586275451496126)
(-10.187845304490947, 0.0892935867062234)
(-47.90417610749193, 0.0204470828020304)
(52.61683371795014, -0.0193726157649153)
(-41.620237171074066, 0.02346141784367)
(-85.60551319013732, 0.0115464165970439)
(55.7587042438767, -0.0182611756271808)
(74.60942927097814, -0.0135849026536422)
(-2.2805702156323617, -0.301345089868793)
(-76.18038272979369, 0.0129563884100013)
(54.18777308448308, 0.0188004828697393)
(11.757750103109899, -0.0928559995735437)
(-5.459159449624282, -0.154357125599364)
(-84.03466353987932, -0.011759706828775)
(-0.637196330969125, 0.584165185611747)
(-11.761392127115943, -0.0783012785650106)
(-62.04248941210236, -0.0158618188965606)
(-38.47817773258804, 0.0253284184609493)
(96.60135909614404, -0.0104599592831864)
(10.182978698048352, 0.108736064581312)
(63.61325855549712, 0.0159705490539322)
(25.908103845856804, 0.040139489885367)
(-33.76493036694237, -0.0287616451426903)
(40.048904454856334, -0.0256068139934971)
(-40.04921638419398, -0.0243591940123493)
(-49.47513152193626, -0.0198107644368111)
(93.45967758928009, -0.0108153673519588)
(69.89680799094245, 0.0145140783224103)
(68.3259270041136, -0.014852709331234)
(-54.18794342343466, 0.0181191560900984)
(-57.32978005762594, 0.0171432716164381)
(-46.33321013300211, -0.0211256369273738)
(84.03459272656133, -0.0120429550853916)
(91.8888345323567, 0.0110022850853576)
(22.765062460177248, 0.0459330744456629)
(82.46373834518636, 0.0122751691140578)
(85.6054449521595, 0.0118193638511416)
(90.317989831739, -0.0111957773969401)
(60.471454983255995, 0.0168141953145683)
(-77.75124366596276, -0.0126979562288175)
(88.74714339914914, 0.0113961973799546)
(8.606560646086729, -0.131182360380572)
(-24.337477538813616, -0.0394595455509357)
(46.33297711483998, -0.0220576552494669)
(-18.05103812545779, -0.0524725090383133)
(38.47783979360729, 0.0266800600927598)
(-93.45973483867563, -0.010586373047711)
(-140.5845055255466, -0.00706287570622247)
(99.74303494897006, -0.0101271667464578)
(-90.31805113370845, -0.0109505732775833)
(2.1513443358892483, -0.796668913740646)
(-99.74308521195597, -0.0099261173294882)
(3.8398511253705365, 0.346796963988786)
(41.619948359411254, 0.0246165810275241)
(-3.8758967917372615, 0.204020590583108)
(-98.17224957955716, 0.0100833377779178)
(-25.908849837356932, 0.0371560813395048)
(-69.89691035407965, 0.0141046362542619)
(24.336631932850587, -0.0428412529680419)
(32.19331084678758, 0.0320540376107124)
(-27.480158579577623, -0.0351067542272663)
(-65.18427030127438, -0.0151088991415451)
(30.622089526169745, -0.0337537827722389)
(-60.47159175203532, 0.0162671389088241)
(66.75504197224114, 0.0152075196214254)
(-68.32603412922812, -0.0144242203517829)
(-35.33603756523104, 0.0275182822767101)
(-32.19379374044943, 0.0301226964076625)
(16.47721426950408, 0.0645774211200931)
(-91.88889375607587, 0.0107653937165865)
(62.04235948333203, -0.0163815170913838)
(76.18029655920942, 0.0133010633202575)
(-16.479062504094543, 0.0571879131957477)
(-82.46381188244735, 0.0119810254787546)
(-55.758865116862815, -0.0176177095723664)
(19.621531991288602, 0.0536819267559723)
(47.90395812855178, 0.0213189510240566)
(33.76449140678997, -0.0305172928724435)
(-71.46778311505214, -0.0137989069832578)
(44.76198284117895, 0.0228493928087149)
(-79.32210207500029, 0.0124496321661373)
(-13.33433520456351, 0.0697201640933345)
(71.46768520325605, -0.014190544578759)
(77.75116094270562, -0.0130288424129444)
(98.172197695036, 0.0102908731702446)
(-19.622833974155125, 0.0484756955066268)
(-63.61338214489455, 0.0154762067428617)
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:
$$x_{1} = 18.0494987719381$$
$$x_{2} = 52.6168337179501$$
$$x_{3} = 55.7587042438767$$
$$x_{4} = 74.6094292709781$$
$$x_{5} = -2.28057021563236$$
$$x_{6} = 11.7577501031099$$
$$x_{7} = -5.45915944962428$$
$$x_{8} = -84.0346635398793$$
$$x_{9} = -11.7613921271159$$
$$x_{10} = -62.0424894121024$$
$$x_{11} = 96.601359096144$$
$$x_{12} = -33.7649303669424$$
$$x_{13} = 40.0489044548563$$
$$x_{14} = -40.049216384194$$
$$x_{15} = -49.4751315219363$$
$$x_{16} = 93.4596775892801$$
$$x_{17} = 68.3259270041136$$
$$x_{18} = -46.3332101330021$$
$$x_{19} = 84.0345927265613$$
$$x_{20} = 90.317989831739$$
$$x_{21} = -77.7512436659628$$
$$x_{22} = 8.60656064608673$$
$$x_{23} = -24.3374775388136$$
$$x_{24} = 46.33297711484$$
$$x_{25} = -18.0510381254578$$
$$x_{26} = -93.4597348386756$$
$$x_{27} = -140.584505525547$$
$$x_{28} = 99.7430349489701$$
$$x_{29} = -90.3180511337085$$
$$x_{30} = 2.15134433588925$$
$$x_{31} = -99.743085211956$$
$$x_{32} = 24.3366319328506$$
$$x_{33} = -27.4801585795776$$
$$x_{34} = -65.1842703012744$$
$$x_{35} = 30.6220895261697$$
$$x_{36} = -68.3260341292281$$
$$x_{37} = 62.042359483332$$
$$x_{38} = -55.7588651168628$$
$$x_{39} = 33.76449140679$$
$$x_{40} = -71.4677831150521$$
$$x_{41} = 71.4676852032561$$
$$x_{42} = 77.7511609427056$$
Puntos máximos de la función:
$$x_{42} = -10.1878453044909$$
$$x_{42} = -47.9041761074919$$
$$x_{42} = -41.6202371710741$$
$$x_{42} = -85.6055131901373$$
$$x_{42} = -76.1803827297937$$
$$x_{42} = 54.1877730844831$$
$$x_{42} = -0.637196330969125$$
$$x_{42} = -38.478177732588$$
$$x_{42} = 10.1829786980484$$
$$x_{42} = 63.6132585554971$$
$$x_{42} = 25.9081038458568$$
$$x_{42} = 69.8968079909424$$
$$x_{42} = -54.1879434234347$$
$$x_{42} = -57.3297800576259$$
$$x_{42} = 91.8888345323567$$
$$x_{42} = 22.7650624601772$$
$$x_{42} = 82.4637383451864$$
$$x_{42} = 85.6054449521595$$
$$x_{42} = 60.471454983256$$
$$x_{42} = 88.7471433991491$$
$$x_{42} = 38.4778397936073$$
$$x_{42} = 3.83985112537054$$
$$x_{42} = 41.6199483594113$$
$$x_{42} = -3.87589679173726$$
$$x_{42} = -98.1722495795572$$
$$x_{42} = -25.9088498373569$$
$$x_{42} = -69.8969103540797$$
$$x_{42} = 32.1933108467876$$
$$x_{42} = -60.4715917520353$$
$$x_{42} = 66.7550419722411$$
$$x_{42} = -35.336037565231$$
$$x_{42} = -32.1937937404494$$
$$x_{42} = 16.4772142695041$$
$$x_{42} = -91.8888937560759$$
$$x_{42} = 76.1802965592094$$
$$x_{42} = -16.4790625040945$$
$$x_{42} = -82.4638118824473$$
$$x_{42} = 19.6215319912886$$
$$x_{42} = 47.9039581285518$$
$$x_{42} = 44.7619828411789$$
$$x_{42} = -79.3221020750003$$
$$x_{42} = -13.3343352045635$$
$$x_{42} = 98.172197695036$$
$$x_{42} = -19.6228339741551$$
$$x_{42} = -63.6133821448946$$
Decrece en los intervalos
$$\left[99.7430349489701, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -140.584505525547\right]$$