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$$8 x^{2} \sin{\left(2 x - 1 \right)} - 24 x \cos{\left(2 x - 1 \right)} - 12 \sin{\left(2 x - 1 \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = -13.7454424649031$$
$$x_{2} = -78.0590278387603$$
$$x_{3} = -54.5053777782732$$
$$x_{4} = -100.045955778513$$
$$x_{5} = 17.862344375829$$
$$x_{6} = -18.4305864331261$$
$$x_{7} = -87.4817373771312$$
$$x_{8} = 46.0856186401591$$
$$x_{9} = 10.0715784898416$$
$$x_{10} = -71.7775228591046$$
$$x_{11} = -92.1932505821902$$
$$x_{12} = -62.3558992621817$$
$$x_{13} = -9.08696525527583$$
$$x_{14} = 94.7636058262731$$
$$x_{15} = 61.7853248233988$$
$$x_{16} = 30.3944015566408$$
$$x_{17} = -65.4963397665622$$
$$x_{18} = 97.9046908873213$$
$$x_{19} = 2.56454858441185$$
$$x_{20} = -98.475398463575$$
$$x_{21} = 0.255057292795444$$
$$x_{22} = -56.0754047130423$$
$$x_{23} = -29.396069200616$$
$$x_{24} = 8.52643161023247$$
$$x_{25} = 99.4752454314598$$
$$x_{26} = -51.365464702974$$
$$x_{27} = 25.6909954133979$$
$$x_{28} = -40.3778194956686$$
$$x_{29} = -41.9472296113986$$
$$x_{30} = -10.6348026966634$$
$$x_{31} = 39.8075538658339$$
$$x_{32} = 13.1792214851291$$
$$x_{33} = 47.6553450518662$$
$$x_{34} = 91.6225555444572$$
$$x_{35} = -15.3053493542512$$
$$x_{36} = 16.2994775253611$$
$$x_{37} = 44.5159674615453$$
$$x_{38} = 90.052044581842$$
$$x_{39} = -12.1882244212329$$
$$x_{40} = 33.5313975501223$$
$$x_{41} = 55.5048829432982$$
$$x_{42} = -70.2071935402763$$
$$x_{43} = 5.47402786638968$$
$$x_{44} = 77.4883729226451$$
$$x_{45} = 60.2151607921807$$
$$x_{46} = -34.1014490139235$$
$$x_{47} = -57.645473480912$$
$$x_{48} = -1.71875795960904$$
$$x_{49} = 80.6292120555262$$
$$x_{50} = 24.1239643752974$$
$$x_{51} = -76.4886257467472$$
$$x_{52} = 14.738250592123$$
$$x_{53} = 69.63657212598$$
$$x_{54} = -19.9950915027445$$
$$x_{55} = 49.2251395274187$$
$$x_{56} = 68.0662722684833$$
$$x_{57} = -7.54776657204502$$
$$x_{58} = -27.8281322058858$$
$$x_{59} = 66.49599582797$$
$$x_{60} = 75.9179767130818$$
$$x_{61} = -48.2257698009748$$
$$x_{62} = -67.0666004261986$$
$$x_{63} = -85.9112543046859$$
$$x_{64} = -49.7955874100927$$
$$x_{65} = -84.340782888566$$
$$x_{66} = 83.7701076430789$$
$$x_{67} = -3.07154924173024$$
$$x_{68} = -93.7637745287469$$
$$x_{69} = -43.5167393888333$$
$$x_{70} = -95.334307443617$$
$$x_{71} = -79.6294454655589$$
$$x_{72} = 58.6450305613792$$
$$x_{73} = 74.3475973883145$$
$$x_{74} = 31.9627874270162$$
$$x_{75} = 38.238299376953$$
$$x_{76} = 88.4815437417652$$
$$x_{77} = -37.2393483520332$$
$$x_{78} = 22.5574506870232$$
$$x_{79} = -26.2605338391812$$
$$x_{80} = -6.02278540107339$$
$$x_{81} = -63.9261053849685$$
$$x_{82} = 52.3649082708794$$
$$x_{83} = 3.98814189957044$$
$$x_{84} = -21.5604973394978$$
$$x_{85} = 11.6232273660655$$
$$x_{86} = 36.6691762860526$$
$$x_{87} = -35.670317839542$$
$$x_{88} = 96.3341442218117$$
$$x_{89} = 53.9348721067019$$
$$x_{90} = -73.3478721519596$$
$$x_{91} = 82.199653196388$$
Signos de extremos en los puntos:
(-13.745442464903133, 759.77147176229)
(-78.05902783876034, -24376.8480459664)
(-54.50537777827324, 11887.3463371545)
(-100.04595577851272, -40040.7735197272)
(17.862344375828997, 1280.2670996291)
(-18.43058643312613, -1362.75896762812)
(-87.4817373771312, -30616.218085395)
(46.085618640159076, 8499.539091591)
(10.07157848984163, -409.787418144425)
(-71.77752285910461, -20612.0520230781)
(-92.19325058219025, 34002.3823405188)
(-62.35589926218166, -15557.0338458372)
(-9.086965255275832, -334.340707861971)
(94.76360582627314, -35924.5644573929)
(61.78532482339878, 15273.7066301614)
(30.394401556640812, 3699.2834078743)
(-65.49633976656222, -17163.0831380772)
(97.9046908873213, -38345.3144599947)
(2.5645485844118494, 30.5121141140142)
(-98.47539846357498, 38793.6168738508)
(0.2550572927954443, 2.4952478331758)
(-56.07540471304232, -12581.80548193)
(-29.396069200615973, 3460.52069147914)
(8.526431610232473, 294.854960984045)
(99.47524543145977, 39585.2982689435)
(-51.365464702974, 10557.645556377)
(25.69099541339786, -2644.11570708713)
(-40.37781949566862, -6525.47597383058)
(-41.94722961139862, 7042.28283269147)
(-10.63480269666343, 456.432894004919)
(39.80755386583388, 6342.56820281612)
(13.17922148512906, -698.792125794266)
(47.655345051866156, -9088.12962169577)
(91.62255554445724, -33582.7712734673)
(-15.305349354251165, -941.033365595024)
(16.29947752536112, -1066.70824727944)
(44.51596746154533, -7930.68769667754)
(90.05204458184198, 32441.4834877784)
(-12.188224421232922, -598.239785904422)
(33.53139755012229, 4501.42245708499)
(55.504882943298156, 12327.1695786014)
(-70.20719354027626, 19720.2010104971)
(5.474027866389676, 123.972536245951)
(77.48837292264511, 24021.7925011179)
(60.21516079218075, -14507.4635949201)
(-34.10144901392346, -4655.63913920824)
(-57.645473480911974, 13296.0038018907)
(-1.7187579596090397, 15.8983270794995)
(80.62921205552618, 26008.2800380164)
(24.12396437529738, 2331.87024276556)
(-76.48862574674722, 23406.0402424856)
(14.738250592122988, 872.884003284896)
(69.63657212598, -19401.0096360852)
(-19.99509150274451, 1603.2257426745)
(49.225139527418655, 9696.45929620862)
(68.06627226848326, 18536.070651514)
(-7.547766572045018, 231.942817906739)
(-27.82813220588575, -3101.62551216705)
(66.49599582797003, -17690.8708602491)
(75.91797671308176, -23058.1575323844)
(-48.22576980097476, 9306.90141899861)
(-67.06660042619863, 17995.7165693708)
(-85.91125430468587, 29526.9750737694)
(-49.795587410092686, -9922.40391030186)
(-84.34078288856597, -28457.4712648369)
(83.77010764307893, 28073.7243785707)
(-3.0715492417302355, -41.9395531168933)
(-93.76377452874692, -35170.5821668367)
(-43.51673938883327, -7578.82879317638)
(-95.33430744361699, 36358.5211976505)
(-79.62944546555889, 25367.3950492875)
(58.64503056137922, 13760.9597431911)
(74.34759738831451, 22114.2617624372)
(31.962787427016163, -4090.48348660865)
(38.238299376953, -5852.67321572174)
(88.48154374176521, -31319.9349058306)
(-37.23934835203324, -5551.07948671938)
(22.55745068702316, -2039.3630150436)
(-26.26053383918125, 2762.46899101559)
(-6.022785401073386, -149.193422622551)
(-63.92610538496845, 16350.1888975129)
(52.36490827087939, 10972.3361085836)
(3.9881418995704365, -67.7882176786082)
(-21.56049733949778, -1863.42967748705)
(11.623227366065521, 544.428841150467)
(36.669176286052604, 5382.5172823381)
(-35.67031783954202, 5093.48981089821)
(96.33414422181174, 37125.0698562252)
(53.93487210670192, -11639.8832588279)
(-73.34787215195965, 21523.6422319283)
(82.19965319638801, -27031.1326075369)
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:
$$x_{1} = -78.0590278387603$$
$$x_{2} = -100.045955778513$$
$$x_{3} = -18.4305864331261$$
$$x_{4} = -87.4817373771312$$
$$x_{5} = 10.0715784898416$$
$$x_{6} = -71.7775228591046$$
$$x_{7} = -62.3558992621817$$
$$x_{8} = -9.08696525527583$$
$$x_{9} = 94.7636058262731$$
$$x_{10} = -65.4963397665622$$
$$x_{11} = 97.9046908873213$$
$$x_{12} = -56.0754047130423$$
$$x_{13} = 25.6909954133979$$
$$x_{14} = -40.3778194956686$$
$$x_{15} = 13.1792214851291$$
$$x_{16} = 47.6553450518662$$
$$x_{17} = 91.6225555444572$$
$$x_{18} = -15.3053493542512$$
$$x_{19} = 16.2994775253611$$
$$x_{20} = 44.5159674615453$$
$$x_{21} = -12.1882244212329$$
$$x_{22} = 60.2151607921807$$
$$x_{23} = -34.1014490139235$$
$$x_{24} = 69.63657212598$$
$$x_{25} = -27.8281322058858$$
$$x_{26} = 66.49599582797$$
$$x_{27} = 75.9179767130818$$
$$x_{28} = -49.7955874100927$$
$$x_{29} = -84.340782888566$$
$$x_{30} = -3.07154924173024$$
$$x_{31} = -93.7637745287469$$
$$x_{32} = -43.5167393888333$$
$$x_{33} = 31.9627874270162$$
$$x_{34} = 38.238299376953$$
$$x_{35} = 88.4815437417652$$
$$x_{36} = -37.2393483520332$$
$$x_{37} = 22.5574506870232$$
$$x_{38} = -6.02278540107339$$
$$x_{39} = 3.98814189957044$$
$$x_{40} = -21.5604973394978$$
$$x_{41} = 53.9348721067019$$
$$x_{42} = 82.199653196388$$
Puntos máximos de la función:
$$x_{42} = -13.7454424649031$$
$$x_{42} = -54.5053777782732$$
$$x_{42} = 17.862344375829$$
$$x_{42} = 46.0856186401591$$
$$x_{42} = -92.1932505821902$$
$$x_{42} = 61.7853248233988$$
$$x_{42} = 30.3944015566408$$
$$x_{42} = 2.56454858441185$$
$$x_{42} = -98.475398463575$$
$$x_{42} = 0.255057292795444$$
$$x_{42} = -29.396069200616$$
$$x_{42} = 8.52643161023247$$
$$x_{42} = 99.4752454314598$$
$$x_{42} = -51.365464702974$$
$$x_{42} = -41.9472296113986$$
$$x_{42} = -10.6348026966634$$
$$x_{42} = 39.8075538658339$$
$$x_{42} = 90.052044581842$$
$$x_{42} = 33.5313975501223$$
$$x_{42} = 55.5048829432982$$
$$x_{42} = -70.2071935402763$$
$$x_{42} = 5.47402786638968$$
$$x_{42} = 77.4883729226451$$
$$x_{42} = -57.645473480912$$
$$x_{42} = -1.71875795960904$$
$$x_{42} = 80.6292120555262$$
$$x_{42} = 24.1239643752974$$
$$x_{42} = -76.4886257467472$$
$$x_{42} = 14.738250592123$$
$$x_{42} = -19.9950915027445$$
$$x_{42} = 49.2251395274187$$
$$x_{42} = 68.0662722684833$$
$$x_{42} = -7.54776657204502$$
$$x_{42} = -48.2257698009748$$
$$x_{42} = -67.0666004261986$$
$$x_{42} = -85.9112543046859$$
$$x_{42} = 83.7701076430789$$
$$x_{42} = -95.334307443617$$
$$x_{42} = -79.6294454655589$$
$$x_{42} = 58.6450305613792$$
$$x_{42} = 74.3475973883145$$
$$x_{42} = -26.2605338391812$$
$$x_{42} = -63.9261053849685$$
$$x_{42} = 52.3649082708794$$
$$x_{42} = 11.6232273660655$$
$$x_{42} = 36.6691762860526$$
$$x_{42} = -35.670317839542$$
$$x_{42} = 96.3341442218117$$
$$x_{42} = -73.3478721519596$$
Decrece en los intervalos
$$\left[97.9046908873213, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -100.045955778513\right]$$