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$$2 x \cos{\left(x + 1 \right)} + 2 \sin{\left(x + 1 \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 19.4716638479466$$
$$x_{2} = -59.1363725465042$$
$$x_{3} = 13.2127076381121$$
$$x_{4} = -71.6997808455739$$
$$x_{5} = 6.99595954344623$$
$$x_{6} = 53.9963890778611$$
$$x_{7} = 38.2960146150878$$
$$x_{8} = 72.8411549997741$$
$$x_{9} = -62.2771126285488$$
$$x_{10} = -21.4669019371238$$
$$x_{11} = -93.687656640251$$
$$x_{12} = 94.8291208275139$$
$$x_{13} = -2.9025816596713$$
$$x_{14} = 22.6061518286588$$
$$x_{15} = -68.5588270317532$$
$$x_{16} = -49.7147981536679$$
$$x_{17} = -0.52026899271959$$
$$x_{18} = -12.0781798144108$$
$$x_{19} = 1.24679137687774$$
$$x_{20} = -96.8289030622188$$
$$x_{21} = -24.6025687023826$$
$$x_{22} = -65.417934536029$$
$$x_{23} = 60.2776451215302$$
$$x_{24} = -99.9701712382329$$
$$x_{25} = -15.2028494649391$$
$$x_{26} = -118.818140534187$$
$$x_{27} = 82.2643606537498$$
$$x_{28} = 75.9821802337515$$
$$x_{29} = -30.8775049299126$$
$$x_{30} = 32.0179451984154$$
$$x_{31} = -90.5464342355346$$
$$x_{32} = 10.0943177411687$$
$$x_{33} = 101.111650976312$$
$$x_{34} = 47.7156405519083$$
$$x_{35} = 66.5592651262192$$
$$x_{36} = 88.5466836249472$$
$$x_{37} = 16.3398833066804$$
$$x_{38} = -203.637636800652$$
$$x_{39} = -5.88082214577343$$
$$x_{40} = 3.95975747525199$$
$$x_{41} = 97.9703754007943$$
$$x_{42} = -27.7395715348192$$
$$x_{43} = -87.4052384364358$$
$$x_{44} = 79.1232505037716$$
$$x_{45} = -81.1229390117807$$
$$x_{46} = 44.5755235510474$$
$$x_{47} = -18.3332512943446$$
$$x_{48} = 85.4055062856094$$
$$x_{49} = -34.0161122316173$$
$$x_{50} = -40.2947202239912$$
$$x_{51} = 25.74236450316$$
$$x_{52} = 63.418416382217$$
$$x_{53} = 28.8797427274828$$
$$x_{54} = -77.9818428080439$$
$$x_{55} = -84.2640722170426$$
$$x_{56} = 41.4356299587436$$
$$x_{57} = -46.5745611270113$$
$$x_{58} = -55.9957280448611$$
$$x_{59} = 57.1369641096559$$
$$x_{60} = -8.96506651296683$$
$$x_{61} = -52.8551961430023$$
$$x_{62} = 69.7001808865412$$
$$x_{63} = -43.4345199190886$$
$$x_{64} = 35.1567518873749$$
$$x_{65} = 91.6878894142842$$
$$x_{66} = -74.8407882621237$$
$$x_{67} = -37.1552231369057$$
$$x_{68} = 50.8559396371055$$
Signos de extremos en los puntos:
(19.471663847946616, 38.8920723838579)
(-59.13637254650418, 118.255838652094)
(13.21270763811213, 26.3500541692845)
(-71.69978084557387, 143.385616681528)
(6.995959543446228, 13.8511331780725)
(53.99638907786112, -107.974263161395)
(38.2960146150878, 76.5659301985075)
(72.84115499977409, -145.668583437025)
(-62.27711262854878, -124.538171098153)
(-21.46690193712382, 42.8872962116735)
(-93.687656640251, -187.36464042778)
(94.82912082751392, 189.647697250559)
(-2.9025816596712968, 5.48856313025098)
(22.606151828658817, -45.1681327256305)
(-68.55882703175322, -137.103070376654)
(-49.71479815366795, -99.4094876739415)
(-0.5202689927195903, -0.480250488310616)
(-12.078179814410767, -24.0739889337502)
(1.2467913768777432, 1.94520590552383)
(-96.82890306221881, 193.647479455616)
(-24.602568702382584, -49.1645415372094)
(-65.41793453602904, 130.820585422592)
(60.27764512153021, -120.538703768476)
(-99.97017123823291, -199.930340243309)
(-15.202849464939055, 30.3401344655561)
(-118.81814053418698, -237.62786529218)
(82.26436065374978, 164.516566722201)
(75.98218023375154, 151.95120119638)
(-30.877504929912625, -61.7226492773339)
(32.01794519841537, 64.0046807427785)
(-90.54643423553456, 181.081825424048)
(10.09431774116865, -20.0902931069925)
(101.1116509763116, 202.213412621014)
(47.71564055190829, -95.4103305161956)
(66.55926512621922, -133.103508591143)
(88.54668362494724, 177.082074852345)
(16.339883306680367, -32.6187380463178)
(-203.63763680065225, 407.270363006534)
(-5.880822145773428, -11.595201002764)
(3.9597574752519944, -7.67844579430347)
(97.97037540079432, -195.930544431928)
(-27.73957153481918, 55.4431285849247)
(-87.4052384364358, -174.79903703406)
(79.1232505037716, -158.23386401133)
(-81.12293901178074, -162.233552458672)
(44.57552355104743, 89.1286217300332)
(-18.333251294344578, -36.6120783037004)
(85.40550628560945, -170.799304928089)
(-34.016112231617306, 68.0028456710553)
(-40.29472022399124, 80.5646347584703)
(25.742364503160008, 51.4459264466301)
(63.41841638221703, 126.821067413982)
(28.879742727482828, -57.7248902139685)
(-77.98184280804387, 155.950863699481)
(-84.26407221704262, 168.516278233476)
(41.43562995874359, -82.8471366356162)
(-46.57456112701128, 93.1276587263507)
(-55.99572804486114, -111.973601855055)
(57.13696410965594, 114.256430434133)
(-8.965066512966832, 17.8196191607336)
(-52.85519614300229, 105.691477748)
(69.70018088654118, 139.386016822569)
(-43.43451991908864, -86.8460258247178)
(35.15675188737488, -70.2850769845122)
(91.68788941428421, -183.364873235689)
(-74.8407882621237, -149.668216615274)
(-37.15522313690572, -74.2835467704278)
(50.85593963710546, 101.692221587932)
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:
$$x_{1} = 53.9963890778611$$
$$x_{2} = 72.8411549997741$$
$$x_{3} = -62.2771126285488$$
$$x_{4} = -93.687656640251$$
$$x_{5} = 22.6061518286588$$
$$x_{6} = -68.5588270317532$$
$$x_{7} = -49.7147981536679$$
$$x_{8} = -0.52026899271959$$
$$x_{9} = -12.0781798144108$$
$$x_{10} = -24.6025687023826$$
$$x_{11} = 60.2776451215302$$
$$x_{12} = -99.9701712382329$$
$$x_{13} = -118.818140534187$$
$$x_{14} = -30.8775049299126$$
$$x_{15} = 10.0943177411687$$
$$x_{16} = 47.7156405519083$$
$$x_{17} = 66.5592651262192$$
$$x_{18} = 16.3398833066804$$
$$x_{19} = -5.88082214577343$$
$$x_{20} = 3.95975747525199$$
$$x_{21} = 97.9703754007943$$
$$x_{22} = -87.4052384364358$$
$$x_{23} = 79.1232505037716$$
$$x_{24} = -81.1229390117807$$
$$x_{25} = -18.3332512943446$$
$$x_{26} = 85.4055062856094$$
$$x_{27} = 28.8797427274828$$
$$x_{28} = 41.4356299587436$$
$$x_{29} = -55.9957280448611$$
$$x_{30} = -43.4345199190886$$
$$x_{31} = 35.1567518873749$$
$$x_{32} = 91.6878894142842$$
$$x_{33} = -74.8407882621237$$
$$x_{34} = -37.1552231369057$$
Puntos máximos de la función:
$$x_{34} = 19.4716638479466$$
$$x_{34} = -59.1363725465042$$
$$x_{34} = 13.2127076381121$$
$$x_{34} = -71.6997808455739$$
$$x_{34} = 6.99595954344623$$
$$x_{34} = 38.2960146150878$$
$$x_{34} = -21.4669019371238$$
$$x_{34} = 94.8291208275139$$
$$x_{34} = -2.9025816596713$$
$$x_{34} = 1.24679137687774$$
$$x_{34} = -96.8289030622188$$
$$x_{34} = -65.417934536029$$
$$x_{34} = -15.2028494649391$$
$$x_{34} = 82.2643606537498$$
$$x_{34} = 75.9821802337515$$
$$x_{34} = 32.0179451984154$$
$$x_{34} = -90.5464342355346$$
$$x_{34} = 101.111650976312$$
$$x_{34} = 88.5466836249472$$
$$x_{34} = -203.637636800652$$
$$x_{34} = -27.7395715348192$$
$$x_{34} = 44.5755235510474$$
$$x_{34} = -34.0161122316173$$
$$x_{34} = -40.2947202239912$$
$$x_{34} = 25.74236450316$$
$$x_{34} = 63.418416382217$$
$$x_{34} = -77.9818428080439$$
$$x_{34} = -84.2640722170426$$
$$x_{34} = -46.5745611270113$$
$$x_{34} = 57.1369641096559$$
$$x_{34} = -8.96506651296683$$
$$x_{34} = -52.8551961430023$$
$$x_{34} = 69.7001808865412$$
$$x_{34} = 50.8559396371055$$
Decrece en los intervalos
$$\left[97.9703754007943, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -118.818140534187\right]$$