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$$- 3 x \sin{\left(x \right)} \cos^{2}{\left(x \right)} + \cos^{3}{\left(x \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = -22.0062945981151$$
$$x_{2} = -94.2513162367499$$
$$x_{3} = 87.9683835225577$$
$$x_{4} = -65.978497833395$$
$$x_{5} = -37.7079514813517$$
$$x_{6} = 37.7079514813517$$
$$x_{7} = 14.1371670969671$$
$$x_{8} = -53.4133156711182$$
$$x_{9} = -75.402644368808$$
$$x_{10} = -43.9898745065796$$
$$x_{11} = 59.6958442217916$$
$$x_{12} = 94.2513162367499$$
$$x_{13} = 50.2721129415958$$
$$x_{14} = 4.71238890099015$$
$$x_{15} = 22.0062945981151$$
$$x_{16} = 72.2612438921163$$
$$x_{17} = -31.426532886749$$
$$x_{18} = -9.45999947251134$$
$$x_{19} = 65.978497833395$$
$$x_{20} = 0.54716075726033$$
$$x_{21} = 7.85398173981436$$
$$x_{22} = 12.5928345144433$$
$$x_{23} = -29.8451300993981$$
$$x_{24} = -12.5928345144433$$
$$x_{25} = -50.2721129415958$$
$$x_{26} = 56.5545617095679$$
$$x_{27} = -14.137166846121$$
$$x_{28} = -97.3927948145887$$
$$x_{29} = 15.7291521688357$$
$$x_{30} = -72.2612438921163$$
$$x_{31} = -15.7291521688357$$
$$x_{32} = -0.54716075726033$$
$$x_{33} = -1.57079644420084$$
$$x_{34} = 1.57079657923741$$
$$x_{35} = 29.8451303157785$$
$$x_{36} = -59.6958442217916$$
$$x_{37} = 20.4203521553001$$
$$x_{38} = 81.6854896627962$$
$$x_{39} = 78.5440602167642$$
$$x_{40} = -81.6854896627962$$
$$x_{41} = -17.2787597501589$$
$$x_{42} = 43.9898745065796$$
$$x_{43} = 42.4115007334065$$
$$x_{44} = -95.8185758684232$$
$$x_{45} = -28.2861176805762$$
$$x_{46} = -23.5619450053232$$
$$x_{47} = 34.5671619539785$$
$$x_{48} = -36.1283154240079$$
$$x_{49} = -6.33574836234573$$
$$x_{50} = 100.534280521352$$
$$x_{51} = -87.9683835225577$$
$$x_{52} = 28.2861176805762$$
$$x_{53} = 6.33574836234573$$
$$x_{54} = -7.85398150906577$$
Signos de extremos en los puntos:
(-22.006294598115065, 22.9987231789777)
(-94.25131623674994, -93.2495479424962)
(87.96838352255773, 88.9664889364721)
(-65.97849783339504, 66.9759718384914)
(-37.707951481351664, -36.7035319787864)
(37.707951481351664, 38.7035319787864)
(14.13716709696708, 1)
(-53.41331567111824, 54.4101955024623)
(-75.402644368808, -74.4004340670771)
(-43.98987450657957, -42.9860860278184)
(59.695844221791624, -58.6930523997922)
(94.25131623674994, 95.2495479424962)
(50.27211294159583, 51.2687978331174)
(4.712388900990145, 1)
(22.006294598115065, -20.9987231789777)
(72.26124389211625, -71.2589375073279)
(-31.426532886749044, -30.4212302581647)
(-9.459999472511342, 10.4424087338996)
(65.97849783339504, -64.9759718384914)
(0.5471607572603301, 1.34079747220024)
(7.853981739814361, 1)
(12.592834514443268, 13.5796110567852)
(-29.84513009939808, 1)
(-12.592834514443268, -11.5796110567852)
(-50.27211294159583, -49.2687978331174)
(56.554561709567935, 57.5516148309334)
(-14.13716684612103, 1)
(-97.39279481458874, 98.3910835563113)
(15.7291521688357, -14.718562077866)
(-72.26124389211625, 73.2589375073279)
(-15.7291521688357, 16.718562077866)
(-0.5471607572603301, 0.659202527799765)
(-1.5707964442008373, 1)
(1.570796579237414, 1)
(29.845130315778494, 1)
(-59.695844221791624, 60.6930523997922)
(20.42035215530012, 1)
(81.68548966279624, 82.6834493592093)
(78.54406021676424, -77.5419383132867)
(-81.68548966279624, -80.6834493592093)
(-17.278759750158898, 1)
(43.98987450657957, 44.9860860278184)
(42.4115007334065, 1)
(-95.81857586842315, 1)
(-28.286117680576208, 29.280226531362)
(-23.5619450053232, 1)
(34.567161953978456, -33.5623409826661)
(-36.12831542400792, 1)
(-6.335748362345733, -5.30953332777999)
(100.53428052135241, 101.532622734819)
(-87.96838352255773, -86.9664889364721)
(28.286117680576208, -27.280226531362)
(6.335748362345733, 7.30953332777999)
(-7.8539815090657745, 1)
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:
$$x_{1} = -94.2513162367499$$
$$x_{2} = -37.7079514813517$$
$$x_{3} = -75.402644368808$$
$$x_{4} = -43.9898745065796$$
$$x_{5} = 59.6958442217916$$
$$x_{6} = 22.0062945981151$$
$$x_{7} = 72.2612438921163$$
$$x_{8} = -31.426532886749$$
$$x_{9} = 65.978497833395$$
$$x_{10} = -12.5928345144433$$
$$x_{11} = -50.2721129415958$$
$$x_{12} = 15.7291521688357$$
$$x_{13} = -0.54716075726033$$
$$x_{14} = 78.5440602167642$$
$$x_{15} = -81.6854896627962$$
$$x_{16} = 34.5671619539785$$
$$x_{17} = -6.33574836234573$$
$$x_{18} = -87.9683835225577$$
$$x_{19} = 28.2861176805762$$
Puntos máximos de la función:
$$x_{19} = -22.0062945981151$$
$$x_{19} = 87.9683835225577$$
$$x_{19} = -65.978497833395$$
$$x_{19} = 37.7079514813517$$
$$x_{19} = -53.4133156711182$$
$$x_{19} = 94.2513162367499$$
$$x_{19} = 50.2721129415958$$
$$x_{19} = -9.45999947251134$$
$$x_{19} = 0.54716075726033$$
$$x_{19} = 12.5928345144433$$
$$x_{19} = 56.5545617095679$$
$$x_{19} = -97.3927948145887$$
$$x_{19} = -72.2612438921163$$
$$x_{19} = -15.7291521688357$$
$$x_{19} = -59.6958442217916$$
$$x_{19} = 81.6854896627962$$
$$x_{19} = 43.9898745065796$$
$$x_{19} = -28.2861176805762$$
$$x_{19} = 100.534280521352$$
$$x_{19} = 6.33574836234573$$
Decrece en los intervalos
$$\left[78.5440602167642, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -94.2513162367499\right]$$