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$$2 \left(\frac{e^{- 2 x} 2 \cos{\left(x \right)}}{5} + \left(- \frac{6 e^{- 2 x} \sin{\left(x \right)}}{5} + 1\right)\right) e^{2 x} + \left(2 e^{- 2 x} \sin{\left(x \right)} - 2 e^{- 2 x} \cos{\left(x \right)}\right) e^{2 x} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = -7.53223062609839$$
$$x_{2} = -76.6472694585533$$
$$x_{3} = -86.0720474193227$$
$$x_{4} = -4.39088114237964$$
$$x_{5} = -73.5056768049635$$
$$x_{6} = -13.8154163867558$$
$$x_{7} = -48.3729355762452$$
$$x_{8} = -60.9393061906043$$
$$x_{9} = -10.6738237340145$$
$$x_{10} = -1.05689769016997$$
$$x_{11} = -16.9570090403472$$
$$x_{12} = -35.806564961886$$
$$x_{13} = -51.5145282298349$$
$$x_{14} = -98.6384180336818$$
$$x_{15} = -20.098601693937$$
$$x_{16} = -0.352584426420149$$
$$x_{17} = -70.3640841513737$$
$$x_{18} = -54.6561208834247$$
$$x_{19} = -67.2224914977839$$
$$x_{20} = -82.9304547657329$$
$$x_{21} = -42.0897502690656$$
$$x_{22} = -32.6649723082962$$
$$x_{23} = -89.2136400729125$$
$$x_{24} = -38.9481576154758$$
$$x_{25} = -26.3817870011166$$
$$x_{26} = -57.7977135370145$$
$$x_{27} = -64.0808988441941$$
$$x_{28} = -92.3552327265023$$
$$x_{29} = -79.7888621121431$$
$$x_{30} = -45.2313429226554$$
$$x_{31} = -23.2401943475268$$
$$x_{32} = -95.496825380092$$
$$x_{33} = -29.5233796547064$$
Signos de extremos en los puntos:
(-7.532230626098393, 1.26491135087281)
(-76.6472694585533, 1.26491106406735)
(-86.07204741932267, -1.26491106406735)
(-4.390881142379643, -1.26475751948553)
(-73.5056768049635, -1.26491106406735)
(-13.815416386755846, 1.26491106406835)
(-48.372935576245155, -1.26491106406735)
(-60.93930619060433, -1.26491106406735)
(-10.67382373401448, -1.26491106353176)
(-1.0568976901699663, 1.36241069617632)
(-16.957009040347224, -1.26491106406735)
(-35.80656496188598, -1.26491106406735)
(-51.514528229834944, 1.26491106406735)
(-98.63841803368184, -1.26491106406735)
(-20.098601693937013, 1.26491106406735)
(-0.3525844264201486, 1.28380778178455)
(-70.3640841513737, 1.26491106406735)
(-54.65612088342474, -1.26491106406735)
(-67.2224914977839, -1.26491106406735)
(-82.93045476573288, 1.26491106406735)
(-42.08975026906557, -1.26491106406735)
(-32.664972308296186, 1.26491106406735)
(-89.21364007291247, 1.26491106406735)
(-38.94815761547577, 1.26491106406735)
(-26.3817870011166, 1.26491106406735)
(-57.79771353701453, 1.26491106406735)
(-64.08089884419412, 1.26491106406735)
(-92.35523272650225, -1.26491106406735)
(-79.78886211214308, -1.26491106406735)
(-45.23134292265536, 1.26491106406735)
(-23.240194347526806, -1.26491106406735)
(-95.49682538009205, 1.26491106406735)
(-29.523379654706392, -1.26491106406735)
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:
$$x_{1} = -86.0720474193227$$
$$x_{2} = -4.39088114237964$$
$$x_{3} = -73.5056768049635$$
$$x_{4} = -48.3729355762452$$
$$x_{5} = -60.9393061906043$$
$$x_{6} = -10.6738237340145$$
$$x_{7} = -16.9570090403472$$
$$x_{8} = -35.806564961886$$
$$x_{9} = -98.6384180336818$$
$$x_{10} = -0.352584426420149$$
$$x_{11} = -54.6561208834247$$
$$x_{12} = -67.2224914977839$$
$$x_{13} = -42.0897502690656$$
$$x_{14} = -92.3552327265023$$
$$x_{15} = -79.7888621121431$$
$$x_{16} = -23.2401943475268$$
$$x_{17} = -29.5233796547064$$
Puntos máximos de la función:
$$x_{17} = -7.53223062609839$$
$$x_{17} = -76.6472694585533$$
$$x_{17} = -13.8154163867558$$
$$x_{17} = -1.05689769016997$$
$$x_{17} = -51.5145282298349$$
$$x_{17} = -20.098601693937$$
$$x_{17} = -70.3640841513737$$
$$x_{17} = -82.9304547657329$$
$$x_{17} = -32.6649723082962$$
$$x_{17} = -89.2136400729125$$
$$x_{17} = -38.9481576154758$$
$$x_{17} = -26.3817870011166$$
$$x_{17} = -57.7977135370145$$
$$x_{17} = -64.0808988441941$$
$$x_{17} = -45.2313429226554$$
$$x_{17} = -95.496825380092$$
Decrece en los intervalos
$$\left[-0.352584426420149, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -98.6384180336818\right]$$