Para hallar los extremos hay que resolver la ecuación
$$\frac{d}{d z} f{\left(z \right)} = 0$$
(la derivada es igual a cero),
y las raíces de esta ecuación serán los extremos de esta función:
$$\frac{d}{d z} f{\left(z \right)} = $$
primera derivada$$- \frac{2 z^{2} \sin{\left(z \right)}}{\left(z^{2} - 1\right)^{2}} + \frac{z \cos{\left(z \right)} + \sin{\left(z \right)}}{z^{2} - 1} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$z_{1} = 64.38711209614$$
$$z_{2} = -23.5192984918928$$
$$z_{3} = -14.0654715664522$$
$$z_{4} = -54.9596662363795$$
$$z_{5} = 199.48612041292$$
$$z_{6} = -89.5242181426111$$
$$z_{7} = -45.531112815032$$
$$z_{8} = 0$$
$$z_{9} = -256.035895465913$$
$$z_{10} = 76.9560219212311$$
$$z_{11} = -67.5294282811446$$
$$z_{12} = -29.8115232181233$$
$$z_{13} = 23.5192984918928$$
$$z_{14} = -64.38711209614$$
$$z_{15} = 36.1005797021386$$
$$z_{16} = -58.1022445549727$$
$$z_{17} = 29.8115232181233$$
$$z_{18} = 86.3822189314905$$
$$z_{19} = 67.5294282811446$$
$$z_{20} = -86.3822189314905$$
$$z_{21} = 4.46996389748549$$
$$z_{22} = 54.9596662363795$$
$$z_{23} = 17.2203623011865$$
$$z_{24} = 48.6741268811873$$
$$z_{25} = 45.531112815032$$
$$z_{26} = -7.7208347779541$$
$$z_{27} = 61.2447215519469$$
$$z_{28} = -39.2443992496797$$
$$z_{29} = -80.0981247364271$$
$$z_{30} = 70.6716800442611$$
$$z_{31} = -95.8081365124445$$
$$z_{32} = 7.7208347779541$$
$$z_{33} = -61.2447215519469$$
$$z_{34} = -10.9025655123245$$
$$z_{35} = 108.375718080332$$
$$z_{36} = 26.6659486334171$$
$$z_{37} = 20.3710658047264$$
$$z_{38} = 98.9500607597783$$
$$z_{39} = 51.8169681067243$$
$$z_{40} = -32.9563331139653$$
$$z_{41} = -83.2401890026084$$
$$z_{42} = -20.3710658047264$$
$$z_{43} = -4.46996389748549$$
$$z_{44} = 42.387887292922$$
$$z_{45} = 73.8138756267966$$
$$z_{46} = 32.9563331139653$$
$$z_{47} = -73.8138756267966$$
$$z_{48} = -51.8169681067243$$
$$z_{49} = -36.1005797021386$$
$$z_{50} = 39.2443992496797$$
$$z_{51} = 83.2401890026084$$
$$z_{52} = 95.8081365124445$$
$$z_{53} = -98.9500607597783$$
$$z_{54} = 10.9025655123245$$
$$z_{55} = -42.387887292922$$
$$z_{56} = -26.6659486334171$$
$$z_{57} = -76.9560219212311$$
$$z_{58} = 58.1022445549727$$
$$z_{59} = -48.6741268811873$$
$$z_{60} = -70.6716800442611$$
$$z_{61} = 14.0654715664522$$
$$z_{62} = 92.6661897639043$$
$$z_{63} = -92.6661897639043$$
$$z_{64} = 80.0981247364271$$
$$z_{65} = 89.5242181426111$$
$$z_{66} = -17.2203623011865$$
Signos de extremos en los puntos:
(64.38711209614003, 0.0155329305638574)
(-23.51929849189281, -0.0425565503632636)
(-14.065471566452166, 0.071273704843965)
(-54.95966623637955, -0.0181981710779705)
(199.48612041292, -0.00501294306442466)
(-89.52421814261109, 0.011170858450225)
(-45.53111281503197, 0.0219682951476771)
(0, 0)
(-256.0358954659132, -0.00390573214421328)
(76.95602192123113, 0.0129955313516866)
(-67.52942828114465, -0.0148099815899088)
(-29.81152321812332, -0.0335629000697628)
(23.51929849189281, -0.0425565503632636)
(-64.38711209614003, 0.0155329305638574)
(36.100579702138575, -0.0277109952385317)
(-58.10224455497274, 0.0172135864769991)
(29.81152321812332, -0.0335629000697628)
(86.38221893149047, -0.0115772319735735)
(67.52942828114465, -0.0148099815899088)
(-86.38221893149047, -0.0115772319735735)
(4.469963897485487, -0.228615608199587)
(54.95966623637955, -0.0181981710779705)
(17.220362301186473, -0.0581679527920454)
(48.67412688118727, -0.0205491275919096)
(45.53111281503197, 0.0219682951476771)
(-7.720834777954096, 0.130563549425582)
(61.244721551946924, -0.0163301129538142)
(-39.24439924967973, 0.0254896034489584)
(-80.09812473642714, -0.0124856594290107)
(70.67168004426111, 0.0141513554601957)
(-95.80813651244455, 0.010438095281174)
(7.720834777954096, 0.130563549425582)
(-61.244721551946924, -0.0163301129538142)
(-10.902565512324477, -0.0920999140067109)
(108.37571808033167, 0.00922755188884025)
(26.665948633417063, 0.0375272953860803)
(20.371065804726353, 0.0491480573048362)
(98.95006075977834, -0.0101066239605399)
(51.816968106724275, 0.0193022884246921)
(-32.9563331139653, 0.0303571212035259)
(-83.24018900260842, 0.0120142944143532)
(-20.371065804726353, 0.0491480573048362)
(-4.469963897485487, -0.228615608199587)
(42.387887292922, -0.0235982021713917)
(73.8138756267966, -0.0135488310588046)
(32.9563331139653, 0.0303571212035259)
(-73.8138756267966, -0.0135488310588046)
(-51.816968106724275, 0.0193022884246921)
(-36.100579702138575, -0.0277109952385317)
(39.24439924967973, 0.0254896034489584)
(83.24018900260842, 0.0120142944143532)
(95.80813651244455, 0.010438095281174)
(-98.95006075977834, -0.0101066239605399)
(10.902565512324477, -0.0920999140067109)
(-42.387887292922, -0.0235982021713917)
(-26.665948633417063, 0.0375272953860803)
(-76.95602192123113, 0.0129955313516866)
(58.10224455497274, 0.0172135864769991)
(-48.67412688118727, -0.0205491275919096)
(-70.67168004426111, 0.0141513554601957)
(14.065471566452166, 0.071273704843965)
(92.66618976390433, -0.0107920506355808)
(-92.66618976390433, -0.0107920506355808)
(80.09812473642714, -0.0124856594290107)
(89.52421814261109, 0.011170858450225)
(-17.220362301186473, -0.0581679527920454)
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:
$$z_{1} = -23.5192984918928$$
$$z_{2} = -54.9596662363795$$
$$z_{3} = 199.48612041292$$
$$z_{4} = -256.035895465913$$
$$z_{5} = -67.5294282811446$$
$$z_{6} = -29.8115232181233$$
$$z_{7} = 23.5192984918928$$
$$z_{8} = 36.1005797021386$$
$$z_{9} = 29.8115232181233$$
$$z_{10} = 86.3822189314905$$
$$z_{11} = 67.5294282811446$$
$$z_{12} = -86.3822189314905$$
$$z_{13} = 4.46996389748549$$
$$z_{14} = 54.9596662363795$$
$$z_{15} = 17.2203623011865$$
$$z_{16} = 48.6741268811873$$
$$z_{17} = 61.2447215519469$$
$$z_{18} = -80.0981247364271$$
$$z_{19} = -61.2447215519469$$
$$z_{20} = -10.9025655123245$$
$$z_{21} = 98.9500607597783$$
$$z_{22} = -4.46996389748549$$
$$z_{23} = 42.387887292922$$
$$z_{24} = 73.8138756267966$$
$$z_{25} = -73.8138756267966$$
$$z_{26} = -36.1005797021386$$
$$z_{27} = -98.9500607597783$$
$$z_{28} = 10.9025655123245$$
$$z_{29} = -42.387887292922$$
$$z_{30} = -48.6741268811873$$
$$z_{31} = 92.6661897639043$$
$$z_{32} = -92.6661897639043$$
$$z_{33} = 80.0981247364271$$
$$z_{34} = -17.2203623011865$$
Puntos máximos de la función:
$$z_{34} = 64.38711209614$$
$$z_{34} = -14.0654715664522$$
$$z_{34} = -89.5242181426111$$
$$z_{34} = -45.531112815032$$
$$z_{34} = 0$$
$$z_{34} = 76.9560219212311$$
$$z_{34} = -64.38711209614$$
$$z_{34} = -58.1022445549727$$
$$z_{34} = 45.531112815032$$
$$z_{34} = -7.7208347779541$$
$$z_{34} = -39.2443992496797$$
$$z_{34} = 70.6716800442611$$
$$z_{34} = -95.8081365124445$$
$$z_{34} = 7.7208347779541$$
$$z_{34} = 108.375718080332$$
$$z_{34} = 26.6659486334171$$
$$z_{34} = 20.3710658047264$$
$$z_{34} = 51.8169681067243$$
$$z_{34} = -32.9563331139653$$
$$z_{34} = -83.2401890026084$$
$$z_{34} = -20.3710658047264$$
$$z_{34} = 32.9563331139653$$
$$z_{34} = -51.8169681067243$$
$$z_{34} = 39.2443992496797$$
$$z_{34} = 83.2401890026084$$
$$z_{34} = 95.8081365124445$$
$$z_{34} = -26.6659486334171$$
$$z_{34} = -76.9560219212311$$
$$z_{34} = 58.1022445549727$$
$$z_{34} = -70.6716800442611$$
$$z_{34} = 14.0654715664522$$
$$z_{34} = 89.5242181426111$$
Decrece en los intervalos
$$\left[199.48612041292, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -256.035895465913\right]$$