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$$- \left(-1 - e^{- x}\right) \sin{\left(x \right)} + e^{- x} \cos{\left(x \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 69.1150383789755$$
$$x_{2} = 65.9734457253857$$
$$x_{3} = 18.8495559150263$$
$$x_{4} = -7.06815775146995$$
$$x_{5} = 6.28131786988297$$
$$x_{6} = 12.5663671270168$$
$$x_{7} = 84.8230016469244$$
$$x_{8} = -19.6349540834516$$
$$x_{9} = -0.568128415352273$$
$$x_{10} = 34.5575191894877$$
$$x_{11} = 97.3893722612836$$
$$x_{12} = -10.2101577271734$$
$$x_{13} = 53.4070751110265$$
$$x_{14} = 59.6902604182061$$
$$x_{15} = 91.106186954104$$
$$x_{16} = 21.9911485748471$$
$$x_{17} = -32.2013246992954$$
$$x_{18} = 9.42469726125225$$
$$x_{19} = 56.5486677646163$$
$$x_{20} = 87.9645943005142$$
$$x_{21} = 43.9822971502571$$
$$x_{22} = 72.2566310325652$$
$$x_{23} = 100.530964914873$$
$$x_{24} = -13.3517679827504$$
$$x_{25} = 31.4159265358979$$
$$x_{26} = 25.1327412287062$$
$$x_{27} = 15.7079631172472$$
$$x_{28} = 81.6814089933346$$
$$x_{29} = 40.8407044966673$$
$$x_{30} = 78.5398163397448$$
$$x_{31} = 28.2743338823076$$
$$x_{32} = 62.8318530717959$$
$$x_{33} = 37.6991118430775$$
$$x_{34} = -25.918139392113$$
$$x_{35} = 50.2654824574367$$
$$x_{36} = -16.4933613969911$$
$$x_{37} = -3.91714018341249$$
$$x_{38} = 47.1238898038469$$
$$x_{39} = -29.0597320457055$$
$$x_{40} = 3.09844813055186$$
$$x_{41} = 94.2477796076938$$
$$x_{42} = 75.398223686155$$
$$x_{43} = -22.7765467384618$$
Signos de extremos en los puntos:
(69.11503837897546, -1)
(65.97344572538566, 1)
(18.849555915026347, -1.00000000651241)
(-7.0681577514699505, -831.192267917444)
(6.2813178698829715, -1.00186918639934)
(12.566367127016816, -1.00000348734844)
(84.82300164692441, 1)
(-19.63495408345158, -238142668.049344)
(-0.5681284153522728, -2.33061153758648)
(34.55751918948773, 1)
(97.3893722612836, 1)
(-10.210157727173357, 19218.7054807096)
(53.40707511102649, 1)
(59.69026041820607, 1)
(91.106186954104, 1)
(21.991148574847127, 1.00000000028143)
(-32.20132469929538, -68287722574252.5)
(9.424697261252247, 1.00008070277378)
(56.548667764616276, -1)
(87.96459430051421, -1)
(43.982297150257104, -1)
(72.25663103256524, 1)
(100.53096491487338, -1)
(-13.351767982750449, -444718.500344877)
(31.41592653589791, -1.00000000000002)
(25.132741228706184, -1.00000000001216)
(15.707963117247239, 1.00000015070174)
(81.68140899333463, -1)
(40.840704496667314, 1)
(78.53981633974483, 1)
(28.274333882307612, 1.00000000000053)
(62.83185307179586, -1)
(37.69911184307752, -1)
(-25.918139392113023, -127523411186.885)
(50.26548245743669, -1)
(-16.493361396991084, 10291078.4687509)
(-3.9171401834124886, 36.5990895529234)
(47.1238898038469, 1)
(-29.059732045705466, 2950980061743.58)
(3.0984481305518594, 1.04414659956003)
(94.2477796076938, -1)
(75.39822368615503, -1)
(-22.776546738461846, 5510786268.42402)
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:
$$x_{1} = 69.1150383789755$$
$$x_{2} = 18.8495559150263$$
$$x_{3} = -7.06815775146995$$
$$x_{4} = 6.28131786988297$$
$$x_{5} = 12.5663671270168$$
$$x_{6} = -19.6349540834516$$
$$x_{7} = -0.568128415352273$$
$$x_{8} = -32.2013246992954$$
$$x_{9} = 56.5486677646163$$
$$x_{10} = 87.9645943005142$$
$$x_{11} = 43.9822971502571$$
$$x_{12} = 100.530964914873$$
$$x_{13} = -13.3517679827504$$
$$x_{14} = 31.4159265358979$$
$$x_{15} = 25.1327412287062$$
$$x_{16} = 81.6814089933346$$
$$x_{17} = 62.8318530717959$$
$$x_{18} = 37.6991118430775$$
$$x_{19} = -25.918139392113$$
$$x_{20} = 50.2654824574367$$
$$x_{21} = 94.2477796076938$$
$$x_{22} = 75.398223686155$$
Puntos máximos de la función:
$$x_{22} = 65.9734457253857$$
$$x_{22} = 84.8230016469244$$
$$x_{22} = 34.5575191894877$$
$$x_{22} = 97.3893722612836$$
$$x_{22} = -10.2101577271734$$
$$x_{22} = 53.4070751110265$$
$$x_{22} = 59.6902604182061$$
$$x_{22} = 91.106186954104$$
$$x_{22} = 21.9911485748471$$
$$x_{22} = 9.42469726125225$$
$$x_{22} = 72.2566310325652$$
$$x_{22} = 15.7079631172472$$
$$x_{22} = 40.8407044966673$$
$$x_{22} = 78.5398163397448$$
$$x_{22} = 28.2743338823076$$
$$x_{22} = -16.4933613969911$$
$$x_{22} = -3.91714018341249$$
$$x_{22} = 47.1238898038469$$
$$x_{22} = -29.0597320457055$$
$$x_{22} = 3.09844813055186$$
$$x_{22} = -22.7765467384618$$
Decrece en los intervalos
$$\left[100.530964914873, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -32.2013246992954\right]$$