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$$- \left(x - 1\right) \sin{\left(x \right)} + \cos{\left(x \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 50.2857695061759$$
$$x_{2} = 40.8657834053267$$
$$x_{3} = -15.7675317799203$$
$$x_{4} = 84.834929283594$$
$$x_{5} = -3.36671587754539$$
$$x_{6} = 81.6938008846843$$
$$x_{7} = -53.4254468020254$$
$$x_{8} = -0.567782020656099$$
$$x_{9} = -25.1709329794757$$
$$x_{10} = 91.1172831492274$$
$$x_{11} = -69.129296788477$$
$$x_{12} = 18.9053472009705$$
$$x_{13} = -109.964754502213$$
$$x_{14} = -34.5856130401369$$
$$x_{15} = 15.7755396389074$$
$$x_{16} = 3.51943605007227$$
$$x_{17} = 34.58728356964$$
$$x_{18} = 22.0386444078516$$
$$x_{19} = 65.9888317703628$$
$$x_{20} = -59.7067315662923$$
$$x_{21} = 59.7072924300783$$
$$x_{22} = 53.4261472496575$$
$$x_{23} = -40.8645864924056$$
$$x_{24} = 72.2706611309075$$
$$x_{25} = 12.6519831342203$$
$$x_{26} = -62.8475141081981$$
$$x_{27} = -56.5660373713478$$
$$x_{28} = -12.6395558422743$$
$$x_{29} = -84.8346514263999$$
$$x_{30} = 37.7263335361973$$
$$x_{31} = -65.9883725804509$$
$$x_{32} = 97.3997453605998$$
$$x_{33} = 87.9760912064584$$
$$x_{34} = -47.1446575542095$$
$$x_{35} = -81.693501252623$$
$$x_{36} = 75.4116616310224$$
$$x_{37} = 56.5666622243178$$
$$x_{38} = 62.8480203293155$$
$$x_{39} = -31.4467365238542$$
$$x_{40} = -91.1170422822337$$
$$x_{41} = 94.2585020796787$$
$$x_{42} = 78.5527100810745$$
$$x_{43} = -22.034534408764$$
$$x_{44} = 25.1740842709126$$
$$x_{45} = -75.411310006954$$
$$x_{46} = -78.5523860109268$$
$$x_{47} = -28.3084405150129$$
$$x_{48} = -87.9758328342401$$
$$x_{49} = 69.1297152082093$$
$$x_{50} = -97.399534561137$$
$$x_{51} = 31.4487567990639$$
$$x_{52} = 9.54132523092565$$
$$x_{53} = -37.7249292642936$$
$$x_{54} = 47.1455569712193$$
$$x_{55} = -100.540812853297$$
$$x_{56} = 44.0055457757373$$
$$x_{57} = -18.8997655344074$$
$$x_{58} = 6.46419193189059$$
$$x_{59} = -9.51955422261535$$
$$x_{60} = 100.541010687502$$
$$x_{61} = 28.3109329053961$$
$$x_{62} = -6.41719900457425$$
$$x_{63} = -72.270278284086$$
$$x_{64} = -556.063694810323$$
$$x_{65} = -94.2582769975219$$
$$x_{66} = 1.28924004659366$$
$$x_{67} = -50.2849788736454$$
$$x_{68} = -113.106099078316$$
$$x_{69} = -44.0045134880243$$
Signos de extremos en los puntos:
(50.28576950617588, 49.2756277212557)
(40.86578340532666, -39.8532472370851)
(-15.76753177992028, 16.7377915569281)
(84.83492928359397, -83.8289658187847)
(-3.3667158775453867, 4.25652882239464)
(81.69380088468426, 80.6876053354428)
(-53.425446802025405, 54.4162622483496)
(-0.5677820206560987, -1.32179043078767)
(-25.170932979475694, -26.151848709355)
(91.1172831492274, -90.1117353362952)
(-69.12929678847702, -70.1221681876335)
(18.905347200970496, 17.8774877381006)
(-109.96475450221315, 110.960248841392)
(-34.58561304013687, 35.5715707342139)
(15.77553963890737, -14.7418157375505)
(3.5194360500722652, -2.34172108723281)
(34.58728356963999, -33.5724068729686)
(22.03864440785156, -21.0149188120813)
(65.98883177036275, -64.9811395066923)
(-59.70673156629228, 60.6984969232027)
(59.70729243007827, -58.6987774534709)
(53.426147249657504, -52.416612625628)
(-40.864586492405614, 41.8526483322311)
(72.27066113090753, -71.2636466570958)
(12.651983134220295, 11.6093075837448)
(-62.84751410819813, -63.8396843902331)
(-56.566037371347775, -57.5573536597393)
(-12.639555842274314, -13.6030448832755)
(-84.83465142639987, 85.8288268660524)
(37.72633353619732, 36.7127268920407)
(-65.98837258045087, 66.9809098458042)
(97.39974536059977, -96.3945590434741)
(87.97609120645843, 86.9703430700788)
(-47.144657554209545, 48.1342755450787)
(-81.69350125262304, -82.6874554913451)
(75.41166163102243, 74.404943164129)
(56.566662224317795, 55.5576662083376)
(62.84802032931549, 61.8399375809263)
(-31.44673652385424, -32.4313376227909)
(-91.11704228223367, 92.1116148846623)
(94.2585020796787, 93.2531411005143)
(78.55271008107447, -77.5462636569844)
(-22.034534408764003, 23.0128585051561)
(25.174084270912637, 24.1534274712866)
(-75.41131000695397, -76.4047673134395)
(-78.55238601092682, 79.5461015890774)
(-28.308440515012887, 29.2913954640856)
(-87.97583283424012, -88.9702138631012)
(69.12971520820932, 68.1223774522407)
(-97.39953456113705, 98.3944536298525)
(31.448756799063855, 30.4323490392631)
(9.541325230925654, -8.4833813173875)
(-37.724929264293635, -38.7120241387053)
(47.1455569712193, -46.1347255066802)
(-100.5408128532973, -101.535889083058)
(44.00554577573732, 42.9939240808542)
(-18.89976553440737, -19.8746870972057)
(6.464191931890594, 5.37492331226648)
(-9.519554222615355, 10.4723434206105)
(100.54101068750202, 99.5359880123945)
(28.310932905396143, -27.2926436069057)
(-6.417199004574255, -7.35069340165152)
(-72.27027828408599, 73.2634551878583)
(-556.0636948103229, 557.062797249063)
(-94.25827699752193, -95.2530285435994)
(1.2892400465936646, 0.0803656318022444)
(-50.28497887364538, -51.2752322094434)
(-113.10609907831552, -114.10171744399)
(-44.0045134880243, -44.9934076035393)
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:
$$x_{1} = 40.8657834053267$$
$$x_{2} = 84.834929283594$$
$$x_{3} = -0.567782020656099$$
$$x_{4} = -25.1709329794757$$
$$x_{5} = 91.1172831492274$$
$$x_{6} = -69.129296788477$$
$$x_{7} = 15.7755396389074$$
$$x_{8} = 3.51943605007227$$
$$x_{9} = 34.58728356964$$
$$x_{10} = 22.0386444078516$$
$$x_{11} = 65.9888317703628$$
$$x_{12} = 59.7072924300783$$
$$x_{13} = 53.4261472496575$$
$$x_{14} = 72.2706611309075$$
$$x_{15} = -62.8475141081981$$
$$x_{16} = -56.5660373713478$$
$$x_{17} = -12.6395558422743$$
$$x_{18} = 97.3997453605998$$
$$x_{19} = -81.693501252623$$
$$x_{20} = -31.4467365238542$$
$$x_{21} = 78.5527100810745$$
$$x_{22} = -75.411310006954$$
$$x_{23} = -87.9758328342401$$
$$x_{24} = 9.54132523092565$$
$$x_{25} = -37.7249292642936$$
$$x_{26} = 47.1455569712193$$
$$x_{27} = -100.540812853297$$
$$x_{28} = -18.8997655344074$$
$$x_{29} = 28.3109329053961$$
$$x_{30} = -6.41719900457425$$
$$x_{31} = -94.2582769975219$$
$$x_{32} = -50.2849788736454$$
$$x_{33} = -113.106099078316$$
$$x_{34} = -44.0045134880243$$
Puntos máximos de la función:
$$x_{34} = 50.2857695061759$$
$$x_{34} = -15.7675317799203$$
$$x_{34} = -3.36671587754539$$
$$x_{34} = 81.6938008846843$$
$$x_{34} = -53.4254468020254$$
$$x_{34} = 18.9053472009705$$
$$x_{34} = -109.964754502213$$
$$x_{34} = -34.5856130401369$$
$$x_{34} = -59.7067315662923$$
$$x_{34} = -40.8645864924056$$
$$x_{34} = 12.6519831342203$$
$$x_{34} = -84.8346514263999$$
$$x_{34} = 37.7263335361973$$
$$x_{34} = -65.9883725804509$$
$$x_{34} = 87.9760912064584$$
$$x_{34} = -47.1446575542095$$
$$x_{34} = 75.4116616310224$$
$$x_{34} = 56.5666622243178$$
$$x_{34} = 62.8480203293155$$
$$x_{34} = -91.1170422822337$$
$$x_{34} = 94.2585020796787$$
$$x_{34} = -22.034534408764$$
$$x_{34} = 25.1740842709126$$
$$x_{34} = -78.5523860109268$$
$$x_{34} = -28.3084405150129$$
$$x_{34} = 69.1297152082093$$
$$x_{34} = -97.399534561137$$
$$x_{34} = 31.4487567990639$$
$$x_{34} = 44.0055457757373$$
$$x_{34} = 6.46419193189059$$
$$x_{34} = -9.51955422261535$$
$$x_{34} = 100.541010687502$$
$$x_{34} = -72.270278284086$$
$$x_{34} = -556.063694810323$$
$$x_{34} = 1.28924004659366$$
Decrece en los intervalos
$$\left[97.3997453605998, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -113.106099078316\right]$$