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$$- x e^{- x} + \cos{\left(x \right)} + e^{- x} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 58.1194640914112$$
$$x_{2} = 7.85131482606546$$
$$x_{3} = 83.2522053201295$$
$$x_{4} = 98.9601685880785$$
$$x_{5} = 86.3937979737193$$
$$x_{6} = 48.6946861306418$$
$$x_{7} = 10.9957419458365$$
$$x_{8} = 67.5442420521806$$
$$x_{9} = 42.4115008234622$$
$$x_{10} = 26.7035375554483$$
$$x_{11} = 23.5619449032434$$
$$x_{12} = 39.2699081698724$$
$$x_{13} = 29.8451302091062$$
$$x_{14} = 14.1371574173172$$
$$x_{15} = 73.8274273593601$$
$$x_{16} = 89.5353906273091$$
$$x_{17} = 45.553093477052$$
$$x_{18} = 70.6858347057703$$
$$x_{19} = 76.9690200129499$$
$$x_{20} = 64.4026493985908$$
$$x_{21} = 36.1283155162826$$
$$x_{22} = 17.2787601047215$$
$$x_{23} = 20.4203522220424$$
$$x_{24} = 80.1106126665397$$
$$x_{25} = 54.9778714378214$$
$$x_{26} = 1.4633436590068$$
$$x_{27} = 61.261056745001$$
$$x_{28} = 92.6769832808989$$
$$x_{29} = 4.74495873059003$$
$$x_{30} = 51.8362787842316$$
$$x_{31} = 95.8185759344887$$
$$x_{32} = 32.9867228626927$$
Signos de extremos en los puntos:
(58.119464091411174, 1)
(7.851314826065457, 1.00305248866688)
(83.25220532012952, 1)
(98.96016858807849, -1)
(86.39379797371932, -1)
(48.6946861306418, -1)
(10.995741945836466, -0.999815554704787)
(67.54424205218055, -1)
(42.411500823462205, -1)
(26.70353755544826, 1.00000000006751)
(23.56194490324339, -0.999999998621558)
(39.269908169872416, 1)
(29.845130209106188, -0.999999999996739)
(14.137157417317203, 1.00001024874567)
(73.82742735936014, -1)
(89.53539062730911, 1)
(45.553093477052, 1)
(70.68583470577035, 1)
(76.96902001294994, 1)
(64.40264939859077, 1)
(36.128315516282626, -0.999999999999993)
(17.278760104721528, -0.99999945869441)
(20.420352222042432, 1.00000002764502)
(80.11061266653972, -1)
(54.977871437821385, -1)
(1.4633436590068039, 1.3329395782157)
(61.26105674500097, -1)
(92.6769832808989, -1)
(4.744958730590032, -0.958210239476558)
(51.83627878423159, 1)
(95.81857593448869, 1)
(32.98672286269268, 1.00000000000016)
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:
$$x_{1} = 98.9601685880785$$
$$x_{2} = 86.3937979737193$$
$$x_{3} = 48.6946861306418$$
$$x_{4} = 10.9957419458365$$
$$x_{5} = 67.5442420521806$$
$$x_{6} = 42.4115008234622$$
$$x_{7} = 23.5619449032434$$
$$x_{8} = 29.8451302091062$$
$$x_{9} = 73.8274273593601$$
$$x_{10} = 36.1283155162826$$
$$x_{11} = 17.2787601047215$$
$$x_{12} = 80.1106126665397$$
$$x_{13} = 54.9778714378214$$
$$x_{14} = 61.261056745001$$
$$x_{15} = 92.6769832808989$$
$$x_{16} = 4.74495873059003$$
Puntos máximos de la función:
$$x_{16} = 58.1194640914112$$
$$x_{16} = 7.85131482606546$$
$$x_{16} = 83.2522053201295$$
$$x_{16} = 26.7035375554483$$
$$x_{16} = 39.2699081698724$$
$$x_{16} = 14.1371574173172$$
$$x_{16} = 89.5353906273091$$
$$x_{16} = 45.553093477052$$
$$x_{16} = 70.6858347057703$$
$$x_{16} = 76.9690200129499$$
$$x_{16} = 64.4026493985908$$
$$x_{16} = 20.4203522220424$$
$$x_{16} = 1.4633436590068$$
$$x_{16} = 51.8362787842316$$
$$x_{16} = 95.8185759344887$$
$$x_{16} = 32.9867228626927$$
Decrece en los intervalos
$$\left[98.9601685880785, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, 4.74495873059003\right]$$