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$$- \left(2 x + 1\right) \sin{\left(x \right)} + 2 \cos{\left(x \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = -12.64850014121$$
$$x_{2} = -25.1732487838808$$
$$x_{3} = -18.9038390299029$$
$$x_{4} = 53.425617048068$$
$$x_{5} = 3.39302627455498$$
$$x_{6} = 56.5661894822938$$
$$x_{7} = 37.7252665845726$$
$$x_{8} = 9.52420750805087$$
$$x_{9} = -75.4115719657448$$
$$x_{10} = 50.2851707005576$$
$$x_{11} = -37.7259683523547$$
$$x_{12} = -6.44970449955024$$
$$x_{13} = 12.6423143748731$$
$$x_{14} = -3.46670616835097$$
$$x_{15} = 72.2703720240308$$
$$x_{16} = -15.7733434995656$$
$$x_{17} = 62.8476376690475$$
$$x_{18} = 0.696269839120548$$
$$x_{19} = -69.1296083184295$$
$$x_{20} = 84.8347196701717$$
$$x_{21} = -84.8348585843051$$
$$x_{22} = -50.2855658998982$$
$$x_{23} = -28.3102763278749$$
$$x_{24} = 69.1293991413482$$
$$x_{25} = 25.1716749823811$$
$$x_{26} = 59.7068682917958$$
$$x_{27} = 65.9884847898322$$
$$x_{28} = -87.9760255062228$$
$$x_{29} = -125.671695000226$$
$$x_{30} = -59.7071486648078$$
$$x_{31} = -78.5526275073207$$
$$x_{32} = 81.6935747942071$$
$$x_{33} = 47.1448753388288$$
$$x_{34} = 28.3090312886332$$
$$x_{35} = -47.1453248960698$$
$$x_{36} = 22.0354939271259$$
$$x_{37} = -94.2584449091977$$
$$x_{38} = -53.4259671800873$$
$$x_{39} = 34.5860128618665$$
$$x_{40} = -22.0375457987899$$
$$x_{41} = 40.8648748890387$$
$$x_{42} = -40.865473077863$$
$$x_{43} = 100.540861577829$$
$$x_{44} = -81.6937245934194$$
$$x_{45} = -9.53500986666914$$
$$x_{46} = 6.4265662907479$$
$$x_{47} = 31.4472179490066$$
$$x_{48} = -31.4482273260185$$
$$x_{49} = -97.3996918452035$$
$$x_{50} = 94.2583323776119$$
$$x_{51} = -100.540960487598$$
$$x_{52} = -65.988714345308$$
$$x_{53} = -72.2705634199913$$
$$x_{54} = -34.5868476060207$$
$$x_{55} = 97.3995864537986$$
$$x_{56} = 44.0047628751252$$
$$x_{57} = -44.0052788198049$$
$$x_{58} = -56.5665018357101$$
$$x_{59} = -128.813092076407$$
$$x_{60} = 18.9010539397122$$
$$x_{61} = -1.0601748825407$$
$$x_{62} = 91.1171015134381$$
$$x_{63} = -62.8478907316314$$
$$x_{64} = 78.552465491919$$
$$x_{65} = -91.1172219360647$$
$$x_{66} = 87.9758963326206$$
$$x_{67} = 75.4113961768682$$
$$x_{68} = 15.7693513037718$$
Signos de extremos en los puntos:
(-12.648500141210008, -24.2151015515211)
(-25.17324878388082, -49.3060177064026)
(-18.903839029902947, -36.7534615948653)
(53.425617048068, -107.832694815235)
(3.3930262745549844, -7.54123369500216)
(56.56618948229382, 114.114859488293)
(37.72526658457259, 76.4243858824178)
(9.524207508050871, -19.9493949645634)
(-75.41157196574477, -149.809796642876)
(50.28517070055758, 101.550656337842)
(-37.725968352354734, -74.4250882665036)
(-6.449704499550243, -11.7348126404397)
(12.642314374873074, 26.208867469117)
(-3.466706168350972, 5.62258741075848)
(72.27037202403078, -145.527004137635)
(-15.773343499565579, 30.4814232045169)
(62.84763766904753, 126.679492379497)
(0.6962698391205479, 1.83565189459708)
(-69.12960831842948, -137.24464798613)
(84.83471967017165, -170.657721987522)
(-84.83485858430505, 168.657860925782)
(-50.2855658998982, -99.5510517325365)
(-28.31027632787489, 55.5846295565941)
(69.12939914134816, 139.244438754336)
(25.171674982381056, 51.304440800867)
(59.70686829179576, -120.397130618661)
(65.98848478983224, -132.961931932477)
(-87.97602550622281, -174.940620429129)
(-125.67169500022553, -250.33540135626)
(-59.70714866480777, 118.39741108998)
(-78.55262750732065, 156.092444723165)
(81.6935747942071, 164.374984537798)
(47.14487533882878, -95.2687689934234)
(28.309031288633168, -57.5833825757534)
(-47.14532489606982, 93.2692188034772)
(22.035493927125895, -45.0266788364878)
(-94.2584449091977, -187.506225022375)
(-53.425967180087326, 105.833045100583)
(34.586012861866465, -70.1435416902434)
(-22.03754579878994, 43.0287359885494)
(40.86487488903865, -82.7055852691928)
(-40.865473077862994, 80.7061839057418)
(100.54086157782926, 202.071826896584)
(-81.69372459341942, -162.375134365067)
(-9.535009866669144, 17.9603457903642)
(6.426566290747898, 13.7109792784596)
(31.447217949006586, 63.8631572509322)
(-31.448227326018454, -61.8641679035984)
(-97.3996918452035, 193.789064564391)
(94.25833237761192, 189.506112474957)
(-100.54096048759759, -200.071925818584)
(-65.988714345308, 130.962161553847)
(-72.27056341999133, 143.5271955794)
(-34.58684760602069, 68.1443773065834)
(97.39958645379863, -195.7889591591)
(44.004762875125245, 88.9870647497717)
(-44.00527881980492, -86.9875810274806)
(-56.56650183571013, -112.115171963728)
(-128.81309207640712, 256.618391070808)
(18.90105393971224, 38.7506667645283)
(-1.0601748825407007, -0.547536793420254)
(91.11710151343806, -183.223289009301)
(-62.84789073163143, -124.679745522165)
(78.55246549191897, -158.092282674943)
(-91.11722193606472, 181.223409450059)
(87.97589633262062, 176.940491234665)
(75.41139617686817, 151.809620815361)
(15.76935130377178, -32.4774109562335)
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:
$$x_{1} = -12.64850014121$$
$$x_{2} = -25.1732487838808$$
$$x_{3} = -18.9038390299029$$
$$x_{4} = 53.425617048068$$
$$x_{5} = 3.39302627455498$$
$$x_{6} = 9.52420750805087$$
$$x_{7} = -75.4115719657448$$
$$x_{8} = -37.7259683523547$$
$$x_{9} = -6.44970449955024$$
$$x_{10} = 72.2703720240308$$
$$x_{11} = -69.1296083184295$$
$$x_{12} = 84.8347196701717$$
$$x_{13} = -50.2855658998982$$
$$x_{14} = 59.7068682917958$$
$$x_{15} = 65.9884847898322$$
$$x_{16} = -87.9760255062228$$
$$x_{17} = -125.671695000226$$
$$x_{18} = 47.1448753388288$$
$$x_{19} = 28.3090312886332$$
$$x_{20} = 22.0354939271259$$
$$x_{21} = -94.2584449091977$$
$$x_{22} = 34.5860128618665$$
$$x_{23} = 40.8648748890387$$
$$x_{24} = -81.6937245934194$$
$$x_{25} = -31.4482273260185$$
$$x_{26} = -100.540960487598$$
$$x_{27} = 97.3995864537986$$
$$x_{28} = -44.0052788198049$$
$$x_{29} = -56.5665018357101$$
$$x_{30} = -1.0601748825407$$
$$x_{31} = 91.1171015134381$$
$$x_{32} = -62.8478907316314$$
$$x_{33} = 78.552465491919$$
$$x_{34} = 15.7693513037718$$
Puntos máximos de la función:
$$x_{34} = 56.5661894822938$$
$$x_{34} = 37.7252665845726$$
$$x_{34} = 50.2851707005576$$
$$x_{34} = 12.6423143748731$$
$$x_{34} = -3.46670616835097$$
$$x_{34} = -15.7733434995656$$
$$x_{34} = 62.8476376690475$$
$$x_{34} = 0.696269839120548$$
$$x_{34} = -84.8348585843051$$
$$x_{34} = -28.3102763278749$$
$$x_{34} = 69.1293991413482$$
$$x_{34} = 25.1716749823811$$
$$x_{34} = -59.7071486648078$$
$$x_{34} = -78.5526275073207$$
$$x_{34} = 81.6935747942071$$
$$x_{34} = -47.1453248960698$$
$$x_{34} = -53.4259671800873$$
$$x_{34} = -22.0375457987899$$
$$x_{34} = -40.865473077863$$
$$x_{34} = 100.540861577829$$
$$x_{34} = -9.53500986666914$$
$$x_{34} = 6.4265662907479$$
$$x_{34} = 31.4472179490066$$
$$x_{34} = -97.3996918452035$$
$$x_{34} = 94.2583323776119$$
$$x_{34} = -65.988714345308$$
$$x_{34} = -72.2705634199913$$
$$x_{34} = -34.5868476060207$$
$$x_{34} = 44.0047628751252$$
$$x_{34} = -128.813092076407$$
$$x_{34} = 18.9010539397122$$
$$x_{34} = -91.1172219360647$$
$$x_{34} = 87.9758963326206$$
$$x_{34} = 75.4113961768682$$
Decrece en los intervalos
$$\left[97.3995864537986, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -125.671695000226\right]$$