Para hallar los extremos hay que resolver la ecuación
$$\frac{d}{d n} f{\left(n \right)} = 0$$
(la derivada es igual a cero),
y las raíces de esta ecuación serán los extremos de esta función:
$$\frac{d}{d n} f{\left(n \right)} = $$
primera derivada$$- \frac{\sin{\left(n \right)}}{n} - \frac{\cos{\left(n \right)}}{n^{2}} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$n_{1} = 47.1026627703624$$
$$n_{2} = 84.811211299318$$
$$n_{3} = -50.2455828375744$$
$$n_{4} = -100.521017074687$$
$$n_{5} = -65.9582857893902$$
$$n_{6} = 65.9582857893902$$
$$n_{7} = -78.5270825679419$$
$$n_{8} = -21.945612879981$$
$$n_{9} = 28.2389365752603$$
$$n_{10} = 53.3883466217256$$
$$n_{11} = -87.9532251106725$$
$$n_{12} = -25.0929104121121$$
$$n_{13} = -34.5285657554621$$
$$n_{14} = -69.100567727981$$
$$n_{15} = 94.2371684817036$$
$$n_{16} = -135.08108127842$$
$$n_{17} = -62.8159348889734$$
$$n_{18} = 50.2455828375744$$
$$n_{19} = -91.0952098694071$$
$$n_{20} = 91.0952098694071$$
$$n_{21} = 56.5309801938186$$
$$n_{22} = -53.3883466217256$$
$$n_{23} = -169.640108529775$$
$$n_{24} = -109.946647805931$$
$$n_{25} = -6.12125046689807$$
$$n_{26} = 2.79838604578389$$
$$n_{27} = -47.1026627703624$$
$$n_{28} = 62.8159348889734$$
$$n_{29} = 9.31786646179107$$
$$n_{30} = -2.79838604578389$$
$$n_{31} = -81.6691650818489$$
$$n_{32} = 12.4864543952238$$
$$n_{33} = -31.3840740178899$$
$$n_{34} = -94.2371684817036$$
$$n_{35} = 197.91528455229$$
$$n_{36} = 59.6735041304405$$
$$n_{37} = 97.3791034786112$$
$$n_{38} = 75.3849592185347$$
$$n_{39} = -40.8162093266346$$
$$n_{40} = -15.644128370333$$
$$n_{41} = -37.672573565113$$
$$n_{42} = -12.4864543952238$$
$$n_{43} = 15.644128370333$$
$$n_{44} = 69.100567727981$$
$$n_{45} = -84.811211299318$$
$$n_{46} = 31.3840740178899$$
$$n_{47} = 37.672573565113$$
$$n_{48} = -97.3791034786112$$
$$n_{49} = 6.12125046689807$$
$$n_{50} = 72.2427897046973$$
$$n_{51} = -75.3849592185347$$
$$n_{52} = 34.5285657554621$$
$$n_{53} = 43.9595528888955$$
$$n_{54} = 78.5270825679419$$
$$n_{55} = 40.8162093266346$$
$$n_{56} = 100.521017074687$$
$$n_{57} = 21.945612879981$$
$$n_{58} = -9.31786646179107$$
$$n_{59} = 25.0929104121121$$
$$n_{60} = -72.2427897046973$$
$$n_{61} = -18.7964043662102$$
$$n_{62} = 87.9532251106725$$
$$n_{63} = -59.6735041304405$$
$$n_{64} = -28.2389365752603$$
$$n_{65} = 18.7964043662102$$
$$n_{66} = 81.6691650818489$$
$$n_{67} = -56.5309801938186$$
$$n_{68} = -43.9595528888955$$
Signos de extremos en los puntos:
(47.10266277036235, -0.0212254394164143)
(84.81121129931802, -0.0117900744410766)
(-50.24558283757444, -0.0198983065303553)
(-100.52101707468658, -0.00994767611536293)
(-65.95828578939016, 0.0151593553168405)
(65.95828578939016, -0.0151593553168405)
(-78.52708256794193, 0.0127334276777468)
(-21.945612879981045, 0.0455199604051285)
(28.238936575260272, -0.0353899155541688)
(53.38834662172563, -0.0187273944640866)
(-87.95322511067255, -0.0113689449158811)
(-25.092910412112097, -0.0398202855500511)
(-34.52856575546206, 0.0289493889114503)
(-69.10056772798097, -0.0144701459746764)
(94.23716848170359, 0.01061092686295)
(-135.0810812784199, 0.00740275832666827)
(-62.81593488897342, -0.015917510583426)
(50.24558283757444, 0.0198983065303553)
(-91.09520986940714, 0.0109768642483425)
(91.09520986940714, -0.0109768642483425)
(56.53098019381864, 0.0176866485521696)
(-53.38834662172563, 0.0187273944640866)
(-169.6401085297751, -0.00589472993500857)
(-109.94664780593057, 0.00909494432157336)
(-6.1212504668980685, -0.161228034325064)
(2.798386045783887, -0.336508416918395)
(-47.10266277036235, 0.0212254394164143)
(62.81593488897342, 0.015917510583426)
(9.317866461791066, -0.106707947715237)
(-2.798386045783887, 0.336508416918395)
(-81.66916508184887, -0.0122436055670467)
(12.486454395223781, 0.0798311807800032)
(-31.38407401788986, -0.0318471321112693)
(-94.23716848170359, -0.01061092686295)
(197.91528455229027, -0.00505260236866135)
(59.67350413044053, -0.0167555036571887)
(97.3791034786112, -0.0102686022030809)
(75.38495921853475, 0.0132640786518247)
(-40.81620932663458, 0.0244927205346957)
(-15.644128370333028, 0.0637915530395936)
(-37.67257356511297, -0.0265351630103045)
(-12.486454395223781, -0.0798311807800032)
(15.644128370333028, -0.0637915530395936)
(69.10056772798097, 0.0144701459746764)
(-84.81121129931802, 0.0117900744410766)
(31.38407401788986, 0.0318471321112693)
(37.67257356511297, 0.0265351630103045)
(-97.3791034786112, 0.0102686022030809)
(6.1212504668980685, 0.161228034325064)
(72.24278970469729, -0.0138408859131547)
(-75.38495921853475, -0.0132640786518247)
(34.52856575546206, -0.0289493889114503)
(43.959552888895495, 0.0227423004725314)
(78.52708256794193, -0.0127334276777468)
(40.81620932663458, -0.0244927205346957)
(100.52101707468658, 0.00994767611536293)
(21.945612879981045, -0.0455199604051285)
(-9.317866461791066, 0.106707947715237)
(25.092910412112097, 0.0398202855500511)
(-72.24278970469729, 0.0138408859131547)
(-18.796404366210158, -0.0531265325613881)
(87.95322511067255, 0.0113689449158811)
(-59.67350413044053, 0.0167555036571887)
(-28.238936575260272, 0.0353899155541688)
(18.796404366210158, 0.0531265325613881)
(81.66916508184887, 0.0122436055670467)
(-56.53098019381864, -0.0176866485521696)
(-43.959552888895495, -0.0227423004725314)
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:
$$n_{1} = 47.1026627703624$$
$$n_{2} = 84.811211299318$$
$$n_{3} = -50.2455828375744$$
$$n_{4} = -100.521017074687$$
$$n_{5} = 65.9582857893902$$
$$n_{6} = 28.2389365752603$$
$$n_{7} = 53.3883466217256$$
$$n_{8} = -87.9532251106725$$
$$n_{9} = -25.0929104121121$$
$$n_{10} = -69.100567727981$$
$$n_{11} = -62.8159348889734$$
$$n_{12} = 91.0952098694071$$
$$n_{13} = -169.640108529775$$
$$n_{14} = -6.12125046689807$$
$$n_{15} = 2.79838604578389$$
$$n_{16} = 9.31786646179107$$
$$n_{17} = -81.6691650818489$$
$$n_{18} = -31.3840740178899$$
$$n_{19} = -94.2371684817036$$
$$n_{20} = 197.91528455229$$
$$n_{21} = 59.6735041304405$$
$$n_{22} = 97.3791034786112$$
$$n_{23} = -37.672573565113$$
$$n_{24} = -12.4864543952238$$
$$n_{25} = 15.644128370333$$
$$n_{26} = 72.2427897046973$$
$$n_{27} = -75.3849592185347$$
$$n_{28} = 34.5285657554621$$
$$n_{29} = 78.5270825679419$$
$$n_{30} = 40.8162093266346$$
$$n_{31} = 21.945612879981$$
$$n_{32} = -18.7964043662102$$
$$n_{33} = -56.5309801938186$$
$$n_{34} = -43.9595528888955$$
Puntos máximos de la función:
$$n_{34} = -65.9582857893902$$
$$n_{34} = -78.5270825679419$$
$$n_{34} = -21.945612879981$$
$$n_{34} = -34.5285657554621$$
$$n_{34} = 94.2371684817036$$
$$n_{34} = -135.08108127842$$
$$n_{34} = 50.2455828375744$$
$$n_{34} = -91.0952098694071$$
$$n_{34} = 56.5309801938186$$
$$n_{34} = -53.3883466217256$$
$$n_{34} = -109.946647805931$$
$$n_{34} = -47.1026627703624$$
$$n_{34} = 62.8159348889734$$
$$n_{34} = -2.79838604578389$$
$$n_{34} = 12.4864543952238$$
$$n_{34} = 75.3849592185347$$
$$n_{34} = -40.8162093266346$$
$$n_{34} = -15.644128370333$$
$$n_{34} = 69.100567727981$$
$$n_{34} = -84.811211299318$$
$$n_{34} = 31.3840740178899$$
$$n_{34} = 37.672573565113$$
$$n_{34} = -97.3791034786112$$
$$n_{34} = 6.12125046689807$$
$$n_{34} = 43.9595528888955$$
$$n_{34} = 100.521017074687$$
$$n_{34} = -9.31786646179107$$
$$n_{34} = 25.0929104121121$$
$$n_{34} = -72.2427897046973$$
$$n_{34} = 87.9532251106725$$
$$n_{34} = -59.6735041304405$$
$$n_{34} = -28.2389365752603$$
$$n_{34} = 18.7964043662102$$
$$n_{34} = 81.6691650818489$$
Decrece en los intervalos
$$\left[197.91528455229, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -169.640108529775\right]$$