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$$\cos{\left(x \right)} + \frac{1}{x} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 29.8115799030901$$
$$x_{2} = -39.2444240846477$$
$$x_{3} = -83.240191603726$$
$$x_{4} = -80.1230937867295$$
$$x_{5} = 92.6661916492115$$
$$x_{6} = -7.72415319239641$$
$$x_{7} = -36.1559769880743$$
$$x_{8} = -64.3871177170664$$
$$x_{9} = 70.699979453112$$
$$x_{10} = 89.5465582344838$$
$$x_{11} = -73.8409703906111$$
$$x_{12} = 23.5194140147849$$
$$x_{13} = 39.2953592151719$$
$$x_{14} = 20.4692255293053$$
$$x_{15} = -17.336473487102$$
$$x_{16} = 86.3822212589452$$
$$x_{17} = 48.6741398947227$$
$$x_{18} = -89.5242202334874$$
$$x_{19} = 42.3879070002498$$
$$x_{20} = 7.97963107097301$$
$$x_{21} = 36.1006116108761$$
$$x_{22} = -61.2773767058956$$
$$x_{23} = -95.8081382182729$$
$$x_{24} = -92.6877723998433$$
$$x_{25} = 73.8138793572668$$
$$x_{26} = -98.9702728040995$$
$$x_{27} = -11.0859017287718$$
$$x_{28} = 10.9037335277384$$
$$x_{29} = -42.4350684201498$$
$$x_{30} = -136.66659757332$$
$$x_{31} = 4.48766960334109$$
$$x_{32} = 95.829011377113$$
$$x_{33} = -14.0660135689384$$
$$x_{34} = 80.0981276558536$$
$$x_{35} = -54.9960555621608$$
$$x_{36} = -32.9563750616135$$
$$x_{37} = -76.9560252131026$$
$$x_{38} = 76.9820104261667$$
$$x_{39} = -45.5311287148944$$
$$x_{40} = 61.2447280834131$$
$$x_{41} = -48.7152150401823$$
$$x_{42} = -378.559273160246$$
$$x_{43} = 2.07393280909122$$
$$x_{44} = -86.405371586641$$
$$x_{45} = 98.9500623082067$$
$$x_{46} = 33.0170149091969$$
$$x_{47} = 64.4181735917203$$
$$x_{48} = 26.740942117298$$
$$x_{49} = 17.2206571155732$$
$$x_{50} = 45.5750370742992$$
$$x_{51} = 67.5294331532335$$
$$x_{52} = 54.959675275262$$
$$x_{53} = -70.671684294851$$
$$x_{54} = -23.6043227065406$$
$$x_{55} = 58.1366657885594$$
$$x_{56} = -51.8169788924771$$
$$x_{57} = -29.8786052250774$$
$$x_{58} = 51.8555643132686$$
$$x_{59} = 83.2642155700859$$
$$x_{60} = -67.5590444598741$$
$$x_{61} = -20.3712437074438$$
$$x_{62} = -4.91718592528713$$
$$x_{63} = -26.6660278619112$$
$$x_{64} = -58.1022522048044$$
$$x_{65} = 14.2076100006438$$
Signos de extremos en los puntos:
(29.811579903090074, 2.39545966410883)
(-39.2444240846477, 2.67013407432556 + pi*I)
(-83.240191603726, 3.4218024671685 + pi*I)
(-80.12309378672954, 5.38348623629512 + pi*I)
(92.66619164921153, 3.52906192801387)
(-7.724153192396411, 1.05276807871629 + pi*I)
(-36.15597698807427, 4.58745971935673 + pi*I)
(-64.38711771706639, 3.16503419179205 + pi*I)
(70.69997945311201, 5.25834524701093)
(89.54655823448383, 5.49469633668208)
(-73.84097039061113, 5.30182202646354 + pi*I)
(23.519414014784864, 2.15873051023656)
(39.29535921517187, 4.67078256540357)
(20.46922552930527, 4.01772850344127)
(-17.336473487101994, 3.85114759177131 + pi*I)
(86.3822212589452, 3.45884889158413)
(48.67413989472275, 2.88535894721174)
(-89.52422023348744, 3.49457159400488 + pi*I)
(42.3879070002498, 2.74714143063437)
(7.979631070973006, 3.06900866829692)
(36.100611610876136, 2.58669353596845)
(-61.27737670589561, 5.11527754858578 + pi*I)
(-95.80813821827292, 3.56240210392047 + pi*I)
(-92.68777239984328, 5.52917835682055 + pi*I)
(73.81387935726681, 3.30163855387227)
(-98.97027280409945, 5.59476848318066 + pi*I)
(-11.085901728771786, 3.40159743619408 + pi*I)
(10.903733527738439, 1.39331965512539)
(-42.43506842014976, 4.74769740281946 + pi*I)
(-136.6665975733198, 5.91751759530376 + pi*I)
(4.487669603341088, 0.526476870263692)
(95.82901137711305, 5.56251102314145)
(-14.066013568938363, 1.64629183591794 + pi*I)
(80.09812765585362, 3.38333041545168)
(-54.99605556216085, 5.00709613897575 + pi*I)
(-32.95637506161347, 2.49564517823999 + pi*I)
(-76.95602521310259, 3.34331858880818 + pi*I)
(76.9820104261667, 5.3434873894975)
(-45.53112871489442, 2.81863745530493 + pi*I)
(61.24472808341312, 3.11501108324549)
(-48.71521504018234, 4.88578069445421 + pi*I)
(-378.55927316024594, 4.93637614979233 + pi*I)
(2.073932809091215, 1.6055212505354)
(-86.40537158664104, 5.4589828715087 + pi*I)
(98.9500623082067, 3.59466636975399)
(33.017014909196874, 4.49656426293951)
(64.41817359172032, 5.16527529406283)
(26.740942117297966, 4.28549633449931)
(17.220657115573236, 1.84779713252751)
(45.57503707429922, 4.81911938297399)
(67.52943315323353, 3.21267319929242)
(54.959675275261986, 3.00676528511167)
(-70.671684294851, 3.25814510304968 + pi*I)
(-23.60432270654059, 4.16053205600252 + pi*I)
(58.13666578855936, 5.06264859996401)
(-51.816978892477124, 2.94790411053493 + pi*I)
(-29.87860522507741, 4.39658244393214 + pi*I)
(51.855564313268616, 4.94827628445491)
(83.26421557008594, 5.42194674969671)
(-67.55904445987407, 5.21289239462526 + pi*I)
(-20.371243707443842, 2.01532986629228 + pi*I)
(-4.917185925287132, 2.5718387001487 + pi*I)
(-26.666027861911218, 2.28409379661875 + pi*I)
(-58.10225220480441, 3.0623525482524 + pi*I)
(14.20761000064383, 3.65129765009562)
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:
$$x_{1} = 29.8115799030901$$
$$x_{2} = 92.6661916492115$$
$$x_{3} = 23.5194140147849$$
$$x_{4} = 86.3822212589452$$
$$x_{5} = 48.6741398947227$$
$$x_{6} = 42.3879070002498$$
$$x_{7} = 36.1006116108761$$
$$x_{8} = 73.8138793572668$$
$$x_{9} = 10.9037335277384$$
$$x_{10} = 4.48766960334109$$
$$x_{11} = 80.0981276558536$$
$$x_{12} = 61.2447280834131$$
$$x_{13} = 98.9500623082067$$
$$x_{14} = 17.2206571155732$$
$$x_{15} = 67.5294331532335$$
$$x_{16} = 54.959675275262$$
Puntos máximos de la función:
$$x_{16} = 70.699979453112$$
$$x_{16} = 89.5465582344838$$
$$x_{16} = 39.2953592151719$$
$$x_{16} = 20.4692255293053$$
$$x_{16} = 7.97963107097301$$
$$x_{16} = 95.829011377113$$
$$x_{16} = 76.9820104261667$$
$$x_{16} = 2.07393280909122$$
$$x_{16} = 33.0170149091969$$
$$x_{16} = 64.4181735917203$$
$$x_{16} = 26.740942117298$$
$$x_{16} = 45.5750370742992$$
$$x_{16} = 58.1366657885594$$
$$x_{16} = 51.8555643132686$$
$$x_{16} = 83.2642155700859$$
$$x_{16} = 14.2076100006438$$
Decrece en los intervalos
$$\left[98.9500623082067, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, 4.48766960334109\right]$$