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$$- 6 \sin{\left(x \right)} \cos^{2}{\left(x \right)} + \frac{1}{x} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = -7.99960692517173$$
$$x_{2} = -83.2969738178074$$
$$x_{3} = 72.2543243512315$$
$$x_{4} = -39.3351166347041$$
$$x_{5} = -21.9835666459728$$
$$x_{6} = -51.7794681257968$$
$$x_{7} = -75.4004341192736$$
$$x_{8} = -43.9860862906991$$
$$x_{9} = -89.5785583974263$$
$$x_{10} = -28.268437786183$$
$$x_{11} = 45.6136332143689$$
$$x_{12} = 58.1730540345467$$
$$x_{13} = -70.7344235192801$$
$$x_{14} = -70.6372124037413$$
$$x_{15} = 20.3294956968854$$
$$x_{16} = 78.5376942053477$$
$$x_{17} = -50.268798009246$$
$$x_{18} = 65.9709193408908$$
$$x_{19} = -95.7768304451449$$
$$x_{20} = -45.6136332143689$$
$$x_{21} = -65.9709193408908$$
$$x_{22} = -59.6874680701942$$
$$x_{23} = 12.5796222695488$$
$$x_{24} = 81.6834494002643$$
$$x_{25} = 34.5526955081915$$
$$x_{26} = -81.6834494002643$$
$$x_{27} = -53.4039542080325$$
$$x_{28} = -9.40705426568954$$
$$x_{29} = 56.5516149546433$$
$$x_{30} = 43.9860862906991$$
$$x_{31} = -6.30962154068306$$
$$x_{32} = 89.5785583974263$$
$$x_{33} = -72.2543243512315$$
$$x_{34} = 6.30962154068306$$
$$x_{35} = -87.9664889693436$$
$$x_{36} = 14.2458647707014$$
$$x_{37} = 1.88077893345191$$
$$x_{38} = 37.7035323961616$$
$$x_{39} = 50.268798009246$$
$$x_{40} = 87.9664889693436$$
$$x_{41} = -95.8603032179737$$
$$x_{42} = -15.6973443638602$$
$$x_{43} = 94.2495479692224$$
$$x_{44} = 26.6242097273469$$
$$x_{45} = -14.0276182978701$$
$$x_{46} = -1.88077893345191$$
$$x_{47} = 15.6973443638602$$
$$x_{48} = -94.2495479692224$$
$$x_{49} = 95.8603032179737$$
$$x_{50} = 21.9835666459728$$
$$x_{51} = 51.8930270808787$$
$$x_{52} = -64.3517029200816$$
$$x_{53} = -37.7035323961616$$
$$x_{54} = 28.268437786183$$
$$x_{55} = 64.3517029200816$$
$$x_{56} = 59.6874680701942$$
$$x_{57} = 70.6372124037413$$
$$x_{58} = 3.08742504955347$$
$$x_{59} = -58.0658245702513$$
$$x_{60} = -97.3876608818886$$
$$x_{61} = 937.75207456793$$
$$x_{62} = 39.2045908573273$$
$$x_{63} = -31.4212309791897$$
$$x_{64} = 100.532622756841$$
$$x_{65} = 7.99960692517173$$
$$x_{66} = -20.3294956968854$$
$$x_{67} = 32.9154136883458$$
$$x_{68} = 97.3876608818886$$
Signos de extremos en los puntos:
(-7.999606925171734, 1.17189341489522 + pi*I)
(-83.2969738178074, 3.52084523652315 + pi*I)
(72.25432435123146, 1.37882042876854)
(-39.33511663470405, 2.77017658798915 + pi*I)
(-21.98356664597275, 0.189079943433468 + pi*I)
(-51.779468125796804, 3.04597210700263 + pi*I)
(-75.40043411927357, 5.42141066321356 + pi*I)
(-43.98608629069909, 4.88244257951702 + pi*I)
(-89.57855839742632, 3.59356754373643 + pi*I)
(-28.268437786182986, 0.440462488098656 + pi*I)
(45.613633214368875, 2.91837598355398)
(58.17305403454667, 3.16172718082829)
(-70.7344235192801, 3.35731548534626 + pi*I)
(-70.63721240374134, 3.35639900927717 + pi*I)
(20.32949569688541, 2.11217895575701)
(78.53769420534775, 1.46220448949404)
(-50.268798009245955, 5.01596387694949 + pi*I)
(65.97091934089076, 1.28784546533221)
(-95.77683044514492, 3.66077846282114 + pi*I)
(-45.613633214368875, 2.91837598355398 + pi*I)
(-65.97091934089076, 1.28784546533221 + pi*I)
(-59.68746807019421, 1.18775776347515 + pi*I)
(12.57962226954883, 3.63016374808887)
(81.68344940026425, 5.5014512025413)
(34.552695508191476, 0.641167656198109)
(-81.68344940026425, 5.5014512025413 + pi*I)
(-53.403954208032545, 1.07652630067281 + pi*I)
(-9.407054265689542, -0.65898563427642 + pi*I)
(56.551614954643334, 5.13373999116279)
(43.98608629069909, 4.88244257951702)
(-6.309621540683057, 2.9385922169633 + pi*I)
(89.57855839742632, 3.59356754373643)
(-72.25432435123146, 1.37882042876854 + pi*I)
(6.309621540683057, 2.9385922169633)
(-87.96648896934359, 5.57555745416694 + pi*I)
(14.245864770701424, 1.75252551996435)
(1.8807789334519098, -0.326470429795601)
(37.70353239616164, 4.7283074530432)
(50.268798009245955, 5.01596387694949)
(87.96648896934359, 5.57555745416694)
(-95.86030321797365, 3.6613590637131 + pi*I)
(-15.697344363860205, -0.147557900962119 + pi*I)
(94.24954796922239, 5.64454893761183)
(26.624209727346887, 2.38142849836729)
(-14.02761829787005, 1.74225403991162 + pi*I)
(-1.8807789334519098, -0.326470429795601 + pi*I)
(15.697344363860205, -0.147557900962119)
(-94.24954796922239, 5.64454893761183 + pi*I)
(95.86030321797365, 3.6613590637131)
(21.98356664597275, 0.189079943433468)
(51.893027080878745, 3.04743180402748)
(-64.35170292008156, 3.26323981035881 + pi*I)
(-37.70353239616164, 4.7283074530432 + pi*I)
(28.268437786182986, 0.440462488098656)
(64.35170292008156, 3.26323981035881)
(59.68746807019421, 1.18775776347515)
(70.63721240374134, 3.35639900927717)
(3.0874250495534685, -1.7652629502561)
(-58.065824570251344, 3.16049778138377 + pi*I)
(-97.38766088188859, 1.67732059274379 + pi*I)
(937.75207456793, 5.94210262937136)
(39.20459085732729, 2.76796228772829)
(-31.421230979189666, 4.54601168896233 + pi*I)
(100.53262275684067, 5.70908632273352)
(7.999606925171734, 1.17189341489522)
(-20.32949569688541, 2.11217895575701 + pi*I)
(32.91541368834582, 2.59327671013379)
(97.38766088188859, 1.67732059274379)
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:
$$x_{1} = 72.2543243512315$$
$$x_{2} = 20.3294956968854$$
$$x_{3} = 78.5376942053477$$
$$x_{4} = 65.9709193408908$$
$$x_{5} = 34.5526955081915$$
$$x_{6} = 26.6242097273469$$
$$x_{7} = 15.6973443638602$$
$$x_{8} = 21.9835666459728$$
$$x_{9} = 28.268437786183$$
$$x_{10} = 64.3517029200816$$
$$x_{11} = 59.6874680701942$$
$$x_{12} = 70.6372124037413$$
$$x_{13} = 3.08742504955347$$
$$x_{14} = 937.75207456793$$
$$x_{15} = 39.2045908573273$$
$$x_{16} = 32.9154136883458$$
$$x_{17} = 97.3876608818886$$
Puntos máximos de la función:
$$x_{17} = 45.6136332143689$$
$$x_{17} = 58.1730540345467$$
$$x_{17} = 12.5796222695488$$
$$x_{17} = 81.6834494002643$$
$$x_{17} = 56.5516149546433$$
$$x_{17} = 43.9860862906991$$
$$x_{17} = 89.5785583974263$$
$$x_{17} = 6.30962154068306$$
$$x_{17} = 14.2458647707014$$
$$x_{17} = 1.88077893345191$$
$$x_{17} = 37.7035323961616$$
$$x_{17} = 50.268798009246$$
$$x_{17} = 87.9664889693436$$
$$x_{17} = 94.2495479692224$$
$$x_{17} = 95.8603032179737$$
$$x_{17} = 51.8930270808787$$
$$x_{17} = 100.532622756841$$
$$x_{17} = 7.99960692517173$$
Decrece en los intervalos
$$\left[937.75207456793, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, 3.08742504955347\right]$$