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$$\frac{\left(20 x \sin{\left(2 x \right)} - 10 x \cos{\left(2 x \right)} + 3 \sin{\left(2 x \right)} - 4 \cos{\left(2 x \right)}\right) e^{2}}{25} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 64.6352443879741$$
$$x_{2} = -72.0255033591792$$
$$x_{3} = -35.8978923510335$$
$$x_{4} = -67.3131632574602$$
$$x_{5} = -94.0164887583458$$
$$x_{6} = -100.2996406125$$
$$x_{7} = -79.8794163763463$$
$$x_{8} = -51.6054276384411$$
$$x_{9} = 45.7860045671659$$
$$x_{10} = 37.9322468707416$$
$$x_{11} = 52.06905917643$$
$$x_{12} = -23.3322825654232$$
$$x_{13} = 100.763283948745$$
$$x_{14} = -70.4547225967174$$
$$x_{15} = 20.6545735900731$$
$$x_{16} = -57.8885070098078$$
$$x_{17} = -64.1716071901995$$
$$x_{18} = -1.38120160239195$$
$$x_{19} = 9.66167172579424$$
$$x_{20} = -7.62888790549685$$
$$x_{21} = -21.7616436866734$$
$$x_{22} = 39.5029913226638$$
$$x_{23} = -26.4736167915785$$
$$x_{24} = -89.3041279638035$$
$$x_{25} = 58.3521418348081$$
$$x_{26} = 86.6261976410267$$
$$x_{27} = 1.82726394043287$$
$$x_{28} = 44.2152466924093$$
$$x_{29} = -78.308632669004$$
$$x_{30} = -45.3223777683704$$
$$x_{31} = 88.1969837349327$$
$$x_{32} = 67.7768014012035$$
$$x_{33} = 80.3430572566921$$
$$x_{34} = -86.1625558175537$$
$$x_{35} = 30.0786053386116$$
$$x_{36} = 31.6493202274584$$
$$x_{37} = 14.3724218304636$$
$$x_{38} = 83.4846266056516$$
$$x_{39} = 61.4936910044344$$
$$x_{40} = 66.2060224730732$$
$$x_{41} = 50.4982924871669$$
$$x_{42} = 53.6398275949959$$
$$x_{43} = 42.6444916370061$$
$$x_{44} = 17.5134060900679$$
$$x_{45} = -50.0346619693212$$
$$x_{46} = -81.4502005716198$$
$$x_{47} = -95.5872763087217$$
$$x_{48} = 0.325795503797285$$
$$x_{49} = -59.4592803626043$$
$$x_{50} = 75.6307068537696$$
$$x_{51} = -28.0443057693738$$
$$x_{52} = -12.33866578552$$
$$x_{53} = -20.1910295447822$$
$$x_{54} = 81.9138417082726$$
$$x_{55} = -37.4686296462638$$
$$x_{56} = 72.4891426972687$$
$$x_{57} = -6.05989325317838$$
$$x_{58} = -42.180868035436$$
$$x_{59} = 6.52244633170316$$
$$x_{60} = 23.7958523877927$$
$$x_{61} = -34.3271604895018$$
$$x_{62} = 96.0509192143605$$
$$x_{63} = 8.09183517436296$$
$$x_{64} = -73.5962847878296$$
$$x_{65} = -15.4794117940065$$
$$x_{66} = 22.2252019991699$$
$$x_{67} = -43.7516214066214$$
$$x_{68} = -92.4457015068628$$
$$x_{69} = -56.3177349431024$$
$$x_{70} = -65.742384785425$$
$$x_{71} = -48.46389829568$$
$$x_{72} = 89.7677701861569$$
$$x_{73} = 36.3615068758865$$
$$x_{74} = 85.0554119241887$$
$$x_{75} = 28.5078993606643$$
$$x_{76} = 15.9428843727392$$
$$x_{77} = -29.6150062107158$$
$$x_{78} = -87.7333417066779$$
$$x_{79} = 74.0599244741303$$
$$x_{80} = -122.290699217015$$
$$x_{81} = -13.9089903135835$$
$$x_{82} = 97.621707199601$$
$$x_{83} = 94.4801315058989$$
$$x_{84} = 59.9229158515985$$
Signos de extremos en los puntos:
2
(64.63524438797407, 28.9948923620801*e )
2
(-72.02550335917921, 32.1210614185897*e )
2
(-35.89789235103348, -15.9640190445123*e )
2
(-67.3131632574602, -30.0136191852217*e )
2
(-94.0164887583458, 41.9557947445377*e )
2
(-100.29964061249967, 44.7657191408808*e )
2
(-79.87941637634631, -35.6334657154449*e )
2
(-51.60542763844109, -22.9888146351093*e )
2
(45.78600456716588, 20.5651288215444*e )
2
(37.93224687074159, -17.0527314711191*e )
2
(52.069059176430024, 23.3750488688439*e )
2
(-23.332282565423245, -10.3442012872768*e )
2
(100.76328394874524, -45.1519539022625*e )
2
(-70.45472259671737, -31.418580641551*e )
2
(20.654573590073127, 9.32548385202523*e )
2
(-57.888507009807775, -25.7987357898477*e )
2
(-64.17160719019948, -28.608657875224*e )
2
(-1.3812016023919491, -0.511276106334118*e )
2
(9.66167172579424, -4.40823309118173*e )
2
(-7.6288879054968515, -3.31959096286351*e )
2
(-21.761643686673448, 9.64172685620577*e )
2
(39.50299132266381, 17.7552106242279*e )
2
(-26.473616791578547, -11.749152675255*e )
2
(-89.30412796380352, -39.8483515857425*e )
2
(58.35214183480807, 26.1849701705871*e )
2
(86.62619764102669, 38.8296242503845*e )
2
(1.8272639404328703, 0.896705738789304*e )
2
(44.21524669240928, -19.862649068112*e )
2
(-78.30863266900396, 34.9309848067047*e )
2
(-45.322377768370444, -20.1788947997625*e )
2
(88.19698373493272, -39.5321052658568*e )
2
(67.77680140120351, 30.3998537143839*e )
2
(80.34305725669208, 36.019700366994*e )
2
(-86.1625558175537, -38.4433895566568*e )
2
(30.078605338611613, 13.5403393161195*e )
2
(31.649320227458396, -14.2428171470094*e )
2
(14.372421830463598, 6.51560418959179*e )
2
(83.48462660565158, 37.4246622709793*e )
2
(61.493691004434396, 27.589931172105*e )
2
(66.20602247307319, -29.6973730193808*e )
2
(50.49829248716687, -22.6725687211968*e )
2
(53.63982759499592, -24.0775290938307*e )
2
(42.64449163700615, 19.1601694407716*e )
2
(17.51340609006795, 7.9205399219896*e )
2
(-50.0346619693212, 22.2863345330862*e )
2
(-81.45020057161976, 36.3359466460064*e )
2
(-95.58727630872174, -42.658275825146*e )
2
(0.3257955037972845, -0.197579404789642*e )
2
(-59.45928036260429, 26.5012162355076*e )
2
(75.63070685376955, -33.9122576729332*e )
2
(-28.044305769373786, 12.451629347221*e )
2
(-12.33866578552004, 5.42691853666759*e )
2
(-20.191029544782236, -8.93925353165252*e )
2
(81.91384170827256, -36.7221813090182*e )
2
(-37.46862964626381, 16.6664978775403*e )
2
(72.48914269726872, -32.5072960011658*e )
2
(-6.059893253178378, 2.61719016207641*e )
2
(-42.18086803543602, -18.7739355619817*e )
2
(6.52244633170316, -3.00337610001784*e )
2
(23.795852387792745, 10.73043276069*e )
2
(-34.32716048950175, 15.2615404545068*e )
2
(96.05091921436053, 43.0445105672703*e )
2
(8.09183517436296, 3.70579456836871*e )
2
(-73.59628478782957, -32.8235422254219*e )
2
(-15.479411794006543, 6.8318436088485*e )
2
(22.225201999169858, -10.0279578147771*e )
2
(-43.75162140662138, 19.4764151139974*e )
2
(-92.44570150686276, -41.2533136772963*e )
2
(-56.3177349431024, 25.0962554017054*e )
2
(-65.74238478542499, 29.3111385106163*e )
2
(-48.463898295680046, -21.5838545203074*e )
2
(89.76777018615694, 40.234586297309*e )
2
(36.36150687588652, 16.3502525173509*e )
2
(85.05541192418873, -38.1271432517755*e )
2
(28.50789936066434, -12.837861883783*e )
2
(15.942884372739243, -7.21807073205542*e )
2
(-29.615006210715844, -13.1541065319221*e )
2
(-87.73334170667792, 39.1458705629708*e )
2
(74.05992447413026, 33.2097768235707*e )
2
(-122.2906992170149, 54.6004557407121*e )
2
(-13.908990313583539, -6.12937890360175*e )
2
(97.62170719960096, -43.7469916673266*e )
2
(94.4801315058989, -42.342029479592*e )
2
(59.92291585159847, -26.8874506459426*e )
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:
$$x_{1} = -35.8978923510335$$
$$x_{2} = -67.3131632574602$$
$$x_{3} = -79.8794163763463$$
$$x_{4} = -51.6054276384411$$
$$x_{5} = 37.9322468707416$$
$$x_{6} = -23.3322825654232$$
$$x_{7} = 100.763283948745$$
$$x_{8} = -70.4547225967174$$
$$x_{9} = -57.8885070098078$$
$$x_{10} = -64.1716071901995$$
$$x_{11} = -1.38120160239195$$
$$x_{12} = 9.66167172579424$$
$$x_{13} = -7.62888790549685$$
$$x_{14} = -26.4736167915785$$
$$x_{15} = -89.3041279638035$$
$$x_{16} = 44.2152466924093$$
$$x_{17} = -45.3223777683704$$
$$x_{18} = 88.1969837349327$$
$$x_{19} = -86.1625558175537$$
$$x_{20} = 31.6493202274584$$
$$x_{21} = 66.2060224730732$$
$$x_{22} = 50.4982924871669$$
$$x_{23} = 53.6398275949959$$
$$x_{24} = -95.5872763087217$$
$$x_{25} = 0.325795503797285$$
$$x_{26} = 75.6307068537696$$
$$x_{27} = -20.1910295447822$$
$$x_{28} = 81.9138417082726$$
$$x_{29} = 72.4891426972687$$
$$x_{30} = -42.180868035436$$
$$x_{31} = 6.52244633170316$$
$$x_{32} = -73.5962847878296$$
$$x_{33} = 22.2252019991699$$
$$x_{34} = -92.4457015068628$$
$$x_{35} = -48.46389829568$$
$$x_{36} = 85.0554119241887$$
$$x_{37} = 28.5078993606643$$
$$x_{38} = 15.9428843727392$$
$$x_{39} = -29.6150062107158$$
$$x_{40} = -13.9089903135835$$
$$x_{41} = 97.621707199601$$
$$x_{42} = 94.4801315058989$$
$$x_{43} = 59.9229158515985$$
Puntos máximos de la función:
$$x_{43} = 64.6352443879741$$
$$x_{43} = -72.0255033591792$$
$$x_{43} = -94.0164887583458$$
$$x_{43} = -100.2996406125$$
$$x_{43} = 45.7860045671659$$
$$x_{43} = 52.06905917643$$
$$x_{43} = 20.6545735900731$$
$$x_{43} = -21.7616436866734$$
$$x_{43} = 39.5029913226638$$
$$x_{43} = 58.3521418348081$$
$$x_{43} = 86.6261976410267$$
$$x_{43} = 1.82726394043287$$
$$x_{43} = -78.308632669004$$
$$x_{43} = 67.7768014012035$$
$$x_{43} = 80.3430572566921$$
$$x_{43} = 30.0786053386116$$
$$x_{43} = 14.3724218304636$$
$$x_{43} = 83.4846266056516$$
$$x_{43} = 61.4936910044344$$
$$x_{43} = 42.6444916370061$$
$$x_{43} = 17.5134060900679$$
$$x_{43} = -50.0346619693212$$
$$x_{43} = -81.4502005716198$$
$$x_{43} = -59.4592803626043$$
$$x_{43} = -28.0443057693738$$
$$x_{43} = -12.33866578552$$
$$x_{43} = -37.4686296462638$$
$$x_{43} = -6.05989325317838$$
$$x_{43} = 23.7958523877927$$
$$x_{43} = -34.3271604895018$$
$$x_{43} = 96.0509192143605$$
$$x_{43} = 8.09183517436296$$
$$x_{43} = -15.4794117940065$$
$$x_{43} = -43.7516214066214$$
$$x_{43} = -56.3177349431024$$
$$x_{43} = -65.742384785425$$
$$x_{43} = 89.7677701861569$$
$$x_{43} = 36.3615068758865$$
$$x_{43} = -87.7333417066779$$
$$x_{43} = 74.0599244741303$$
$$x_{43} = -122.290699217015$$
Decrece en los intervalos
$$\left[100.763283948745, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -95.5872763087217\right]$$